31000120021221 has 32 divisors (see below), whose sum is σ = 44533288356480. Its totient is φ = 19068300835584.

The previous prime is 31000120021217. The next prime is 31000120021271. The reversal of 31000120021221 is 12212002100013.

It is not a de Polignac number, because 31000120021221 - 2² = 31000120021217 is a prime.

It is a super-2 number, since 2×31000120021221² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31000120021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31000120021201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1037923930 + ... + 1037953796.

It is an arithmetic number, because the mean of its divisors is an integer number (1391665261140).

Almost surely, 2^{31000120021221} is an apocalyptic number.

It is an amenable number.

31000120021221 is a deficient number, since it is larger than the sum of its proper divisors (13533168335259).

31000120021221 is a wasteful number, since it uses less digits than its factorization.

31000120021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41125.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 31000120021221 its reverse (12212002100013), we get a palindrome (43212122121234).

The spelling of 31000120021221 in words is "thirty-one trillion, one hundred twenty million, twenty-one thousand, two hundred twenty-one".