31000021311 has 32 divisors (see below), whose sum is σ = 49922611200. Its totient is φ = 16715052000.

The previous prime is 31000021309. The next prime is 31000021319. The reversal of 31000021311 is 11312000013.

It is not a de Polignac number, because 31000021311 - 2¹ = 31000021309 is a prime.

It is a super-2 number, since 2×31000021311² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31000021319) 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, 54621 + ... + 254918.

It is an arithmetic number, because the mean of its divisors is an integer number (1560081600).

Almost surely, 2^31000021311 is an apocalyptic number.

31000021311 is a deficient number, since it is larger than the sum of its proper divisors (18922589889).

31000021311 is a wasteful number, since it uses less digits than its factorization.

31000021311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309819.

The product of its (nonzero) digits is 18, while the sum is 12.

Adding to 31000021311 its reverse (11312000013), we get a palindrome (42312021324).

The spelling of 31000021311 in words is "thirty-one billion, twenty-one thousand, three hundred eleven".