21013213131 has 16 divisors (see below), whose sum is σ = 31135444000. Its totient is φ = 14006667744.

The previous prime is 21013213129. The next prime is 21013213147. The reversal of 21013213131 is 13131231012.

21013213131 is a `hidden beast` number, since 210 + 1 + 321 + 3 + 131 = 666.

It is not a de Polignac number, because 21013213131 - 2¹ = 21013213129 is a prime.

It is a super-2 number, since 2×21013213131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013293131) 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, 131625 + ... + 243621.

It is an arithmetic number, because the mean of its divisors is an integer number (1945965250).

Almost surely, 2^21013213131 is an apocalyptic number.

21013213131 is a deficient number, since it is larger than the sum of its proper divisors (10122230869).

21013213131 is a wasteful number, since it uses less digits than its factorization.

21013213131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118955 (or 118949 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21013213131 its reverse (13131231012), we get a palindrome (34144444143).

The spelling of 21013213131 in words is "twenty-one billion, thirteen million, two hundred thirteen thousand, one hundred thirty-one".