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31200313121 = 83375907387
BaseRepresentation
bin11101000011101011…
…101111111100100001
32222112101220010102122
4131003223233330201
51002344240004441
622155550554025
72153113200005
oct350353577441
988471803378
1031200313121
111226084404a
126068b08915
132c32c68c53
14171da1a705
15c291c734b
hex743aeff21

31200313121 has 4 divisors (see below), whose sum is σ = 31576220592. Its totient is φ = 30824405652.

The previous prime is 31200313093. The next prime is 31200313181. The reversal of 31200313121 is 12131300213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12131300213 = 29418320697.

It is a cyclic number.

It is not a de Polignac number, because 31200313121 - 26 = 31200313057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31200313121.

It is not an unprimeable number, because it can be changed into a prime (31200313181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187953611 + ... + 187953776.

It is an arithmetic number, because the mean of its divisors is an integer number (7894055148).

Almost surely, 231200313121 is an apocalyptic number.

It is an amenable number.

31200313121 is a deficient number, since it is larger than the sum of its proper divisors (375907471).

31200313121 is an equidigital number, since it uses as much as digits as its factorization.

31200313121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375907470.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 31200313121 its reverse (12131300213), we get a palindrome (43331613334).

The spelling of 31200313121 in words is "thirty-one billion, two hundred million, three hundred thirteen thousand, one hundred twenty-one".

Divisors: 1 83 375907387 31200313121