21000011131 has 6 divisors (see below), whose sum is σ = 23082656996. Its totient is φ = 19090919100.

The previous prime is 21000011089. The next prime is 21000011147. The reversal of 21000011131 is 13111000012.

It is a de Polignac number, because none of the positive numbers 2^k-21000011131 is a prime.

It is a super-2 number, since 2×21000011131² (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 (21000014131) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86776785 + ... + 86777026.

Almost surely, 2^21000011131 is an apocalyptic number.

21000011131 is a deficient number, since it is larger than the sum of its proper divisors (2082645865).

21000011131 is a wasteful number, since it uses less digits than its factorization.

21000011131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173553833 (or 173553822 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 10.

Adding to 21000011131 its reverse (13111000012), we get a palindrome (34111011143).

The spelling of 21000011131 in words is "twenty-one billion, eleven thousand, one hundred thirty-one".