21002113131 has 16 divisors (see below), whose sum is σ = 28200155424. Its totient is φ = 13903087104.

The previous prime is 21002113129. The next prime is 21002113141. The reversal of 21002113131 is 13131120012.

It is a happy number.

It is not a de Polignac number, because 21002113131 - 2¹ = 21002113129 is a prime.

It is a super-2 number, since 2×21002113131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21002113131.

It is not an unprimeable number, because it can be changed into a prime (21002113141) 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, 200355 + ... + 286611.

It is an arithmetic number, because the mean of its divisors is an integer number (1762509714).

Almost surely, 2^21002113131 is an apocalyptic number.

21002113131 is a deficient number, since it is larger than the sum of its proper divisors (7198042293).

21002113131 is a wasteful number, since it uses less digits than its factorization.

21002113131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86830.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21002113131 its reverse (13131120012), we get a palindrome (34133233143).

The spelling of 21002113131 in words is "twenty-one billion, two million, one hundred thirteen thousand, one hundred thirty-one".