131021399 has 2 divisors, whose sum is σ = 131021400. Its totient is φ = 131021398.

The previous prime is 131021389. The next prime is 131021411. The reversal of 131021399 is 993120131.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131021399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131021309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65510699 + 65510700.

It is an arithmetic number, because the mean of its divisors is an integer number (65510700).

Almost surely, 2^131021399 is an apocalyptic number.

131021399 is a deficient number, since it is larger than the sum of its proper divisors (1).

131021399 is an equidigital number, since it uses as much as digits as its factorization.

131021399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 131021399 is about 11446.4579237422. The cubic root of 131021399 is about 507.9029603120.

The spelling of 131021399 in words is "one hundred thirty-one million, twenty-one thousand, three hundred ninety-nine".