131000021 has 2 divisors, whose sum is σ = 131000022. Its totient is φ = 131000020.

The previous prime is 130999997. The next prime is 131000057. The reversal of 131000021 is 120000131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120670225 + 10329796 = 10985^2 + 3214^2 .

It is a cyclic number.

It is not a de Polignac number, because 131000021 - 2¹⁰ = 130998997 is a prime.

It is a super-2 number, since 2×131000021² = 34322011004000882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 130999972 and 131000008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131000081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65500010 + 65500011.

It is an arithmetic number, because the mean of its divisors is an integer number (65500011).

Almost surely, 2^131000021 is an apocalyptic number.

It is an amenable number.

131000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

131000021 is an equidigital number, since it uses as much as digits as its factorization.

131000021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 131000021 is about 11445.5240596488. The cubic root of 131000021 is about 507.8753349516.

Adding to 131000021 its reverse (120000131), we get a palindrome (251000152).

The spelling of 131000021 in words is "one hundred thirty-one million, twenty-one", and thus it is an aban number.