21011312012031 has 96 divisors (see below), whose sum is σ = 35349805370880. Its totient is φ = 11991650520960.

The previous prime is 21011312012027. The next prime is 21011312012039. The reversal of 21011312012031 is 13021021311012.

It is not a de Polignac number, because 21011312012031 - 2² = 21011312012027 is a prime.

It is a super-2 number, since 2×21011312012031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21011312011995 and 21011312012013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011312012039) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 37732971 + ... + 38285763.

It is an arithmetic number, because the mean of its divisors is an integer number (368227139280).

Almost surely, 2^{21011312012031} is an apocalyptic number.

21011312012031 is a deficient number, since it is larger than the sum of its proper divisors (14338493358849).

21011312012031 is a wasteful number, since it uses less digits than its factorization.

21011312012031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553018 (or 552993 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 21011312012031 its reverse (13021021311012), we get a palindrome (34032333323043).

The spelling of 21011312012031 in words is "twenty-one trillion, eleven billion, three hundred twelve million, twelve thousand, thirty-one".