20031597981987 has 16 divisors (see below), whose sum is σ = 26994665698560. Its totient is φ = 13211674508000.

The previous prime is 20031597981973. The next prime is 20031597982093. The reversal of 20031597981987 is 78918979513002.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20031597981987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20031597981487) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25873839 + ... + 26636792.

It is an arithmetic number, because the mean of its divisors is an integer number (1687166606160).

Almost surely, 2^{20031597981987} is an apocalyptic number.

20031597981987 is a deficient number, since it is larger than the sum of its proper divisors (6963067716573).

20031597981987 is a wasteful number, since it uses less digits than its factorization.

20031597981987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52511994.

The product of its (nonzero) digits is 68584320, while the sum is 69.

The spelling of 20031597981987 in words is "twenty trillion, thirty-one billion, five hundred ninety-seven million, nine hundred eighty-one thousand, nine hundred eighty-seven".