87807377981 has 4 divisors (see below), whose sum is σ = 87808515264. Its totient is φ = 87806240700.

The previous prime is 87807377971. The next prime is 87807377989. The reversal of 87807377981 is 18977370878.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87807377981 is a prime.

It is a super-2 number, since 2×87807377981² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87807377989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 443675 + ... + 610296.

It is an arithmetic number, because the mean of its divisors is an integer number (21952128816).

Almost surely, 2^87807377981 is an apocalyptic number.

It is an amenable number.

87807377981 is a deficient number, since it is larger than the sum of its proper divisors (1137283).

87807377981 is a wasteful number, since it uses less digits than its factorization.

87807377981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1137282.

The product of its (nonzero) digits is 33191424, while the sum is 65.

The spelling of 87807377981 in words is "eighty-seven billion, eight hundred seven million, three hundred seventy-seven thousand, nine hundred eighty-one".