231020999987 has 2 divisors, whose sum is σ = 231020999988. Its totient is φ = 231020999986.

The previous prime is 231020999929. The next prime is 231021000043. The reversal of 231020999987 is 789999020132.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231020999987 is a prime.

It is not a weakly prime, because it can be changed into another prime (231020929987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115510499993 + 115510499994.

It is an arithmetic number, because the mean of its divisors is an integer number (115510499994).

Almost surely, 2^231020999987 is an apocalyptic number.

231020999987 is a deficient number, since it is larger than the sum of its proper divisors (1).

231020999987 is an equidigital number, since it uses as much as digits as its factorization.

231020999987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4408992, while the sum is 59.

The spelling of 231020999987 in words is "two hundred thirty-one billion, twenty million, nine hundred ninety-nine thousand, nine hundred eighty-seven".