31121010100021 has 8 divisors (see below), whose sum is σ = 31133304914400. Its totient is φ = 31108717555632.

The previous prime is 31121010099937. The next prime is 31121010100067. The reversal of 31121010100021 is 12000101012113.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31121010100021 - 2¹¹ = 31121010097973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31121010099974 and 31121010100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121010100091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27123646 + ... + 28247728.

It is an arithmetic number, because the mean of its divisors is an integer number (3891663114300).

Almost surely, 2^{31121010100021} is an apocalyptic number.

It is an amenable number.

31121010100021 is a deficient number, since it is larger than the sum of its proper divisors (12294814379).

31121010100021 is a wasteful number, since it uses less digits than its factorization.

31121010100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134995.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 31121010100021 its reverse (12000101012113), we get a palindrome (43121111112134).

The spelling of 31121010100021 in words is "thirty-one trillion, one hundred twenty-one billion, ten million, one hundred thousand, twenty-one".