87739981 has 4 divisors (see below), whose sum is σ = 100274272. Its totient is φ = 75205692.

The previous prime is 87739979. The next prime is 87740011. The reversal of 87739981 is 18993778.

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 not a de Polignac number, because 87739981 - 2¹ = 87739979 is a prime.

It is a super-2 number, since 2×87739981² = 15396608531760722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87739901) 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, 6267135 + ... + 6267148.

It is an arithmetic number, because the mean of its divisors is an integer number (25068568).

Almost surely, 2^87739981 is an apocalyptic number.

It is an amenable number.

87739981 is a deficient number, since it is larger than the sum of its proper divisors (12534291).

87739981 is a wasteful number, since it uses less digits than its factorization.

87739981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12534290.

The product of its digits is 762048, while the sum is 52.

The square root of 87739981 is about 9366.9622076744. The cubic root of 87739981 is about 444.3574972253.

The spelling of 87739981 in words is "eighty-seven million, seven hundred thirty-nine thousand, nine hundred eighty-one".