21321021131 has 2 divisors, whose sum is σ = 21321021132. Its totient is φ = 21321021130.

The previous prime is 21321021107. The next prime is 21321021149. The reversal of 21321021131 is 13112012312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21321021131 - 2²² = 21316826827 is a prime.

It is a super-2 number, since 2×21321021131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21321020131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660510565 + 10660510566.

It is an arithmetic number, because the mean of its divisors is an integer number (10660510566).

Almost surely, 2^21321021131 is an apocalyptic number.

21321021131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321021131 is an equidigital number, since it uses as much as digits as its factorization.

21321021131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21321021131 its reverse (13112012312), we get a palindrome (34433033443).

The spelling of 21321021131 in words is "twenty-one billion, three hundred twenty-one million, twenty-one thousand, one hundred thirty-one".