21031002121231 has 4 divisors (see below), whose sum is σ = 21031021261264. Its totient is φ = 21030982981200.

The previous prime is 21031002121187. The next prime is 21031002121243. The reversal of 21031002121231 is 13212120013012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21031002121231 - 2³⁷ = 20893563167759 is a prime.

It is a super-2 number, since 2×21031002121231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031002121199 and 21031002121208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031002121531) 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, 7814475 + ... + 10155196.

It is an arithmetic number, because the mean of its divisors is an integer number (5257755315316).

Almost surely, 2^{21031002121231} is an apocalyptic number.

21031002121231 is a deficient number, since it is larger than the sum of its proper divisors (19140033).

21031002121231 is a wasteful number, since it uses less digits than its factorization.

21031002121231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19140032.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 21031002121231 its reverse (13212120013012), we get a palindrome (34243122134243).

The spelling of 21031002121231 in words is "twenty-one trillion, thirty-one billion, two million, one hundred twenty-one thousand, two hundred thirty-one".