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31231003220 = 2251561550161
BaseRepresentation
bin11101000101100000…
…110100101001010100
32222121112122100022222
4131011200310221110
51002430114100340
622203004441512
72153635101344
oct350540645124
988545570288
1031231003220
11122770a5a6a
126077249298
132c39423081
141723b28d24
15c2bc3a8b5
hex745834a54

31231003220 has 12 divisors (see below), whose sum is σ = 65585106804. Its totient is φ = 12492401280.

The previous prime is 31231003211. The next prime is 31231003273. The reversal of 31231003220 is 2230013213.

It can be written as a sum of positive squares in 2 ways, for example, as 23548130116 + 7682873104 = 153454^2 + 87652^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780775061 + ... + 780775100.

It is an arithmetic number, because the mean of its divisors is an integer number (5465425567).

Almost surely, 231231003220 is an apocalyptic number.

It is an amenable number.

31231003220 is an abundant number, since it is smaller than the sum of its proper divisors (34354103584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31231003220 is a wasteful number, since it uses less digits than its factorization.

31231003220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1561550170 (or 1561550168 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 31231003220 its reverse (2230013213), we get a palindrome (33461016433).

The spelling of 31231003220 in words is "thirty-one billion, two hundred thirty-one million, three thousand, two hundred twenty".

Divisors: 1 2 4 5 10 20 1561550161 3123100322 6246200644 7807750805 15615501610 31231003220