21010131100021 has 16 divisors (see below), whose sum is σ = 24230604787200. Its totient is φ = 17844499991808.

The previous prime is 21010131099989. The next prime is 21010131100067. The reversal of 21010131100021 is 12000113101012.

It is a happy number.

It is not a de Polignac number, because 21010131100021 - 2⁵ = 21010131099989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21010131099974 and 21010131100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010131190021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 646861 + ... + 6514498.

It is an arithmetic number, because the mean of its divisors is an integer number (1514412799200).

Almost surely, 2^{21010131100021} is an apocalyptic number.

It is an amenable number.

21010131100021 is a deficient number, since it is larger than the sum of its proper divisors (3220473687179).

21010131100021 is a wasteful number, since it uses less digits than its factorization.

21010131100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7165188.

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

Adding to 21010131100021 its reverse (12000113101012), we get a palindrome (33010244201033).

The spelling of 21010131100021 in words is "twenty-one trillion, ten billion, one hundred thirty-one million, one hundred thousand, twenty-one".