87618981 has 4 divisors (see below), whose sum is σ = 116825312. Its totient is φ = 58412652.

The previous prime is 87618961. The next prime is 87619027. The reversal of 87618981 is 18981678.

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 not a de Polignac number, because 87618981 - 2⁶ = 87618917 is a prime.

It is a super-2 number, since 2×87618981² = 15354171662956722, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87618981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87618961) 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, 14603161 + ... + 14603166.

It is an arithmetic number, because the mean of its divisors is an integer number (29206328).

Almost surely, 2^87618981 is an apocalyptic number.

It is an amenable number.

87618981 is a deficient number, since it is larger than the sum of its proper divisors (29206331).

87618981 is a wasteful number, since it uses less digits than its factorization.

87618981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29206330.

The product of its digits is 193536, while the sum is 48.

The square root of 87618981 is about 9360.5011083809. The cubic root of 87618981 is about 444.1531358389.

The spelling of 87618981 in words is "eighty-seven million, six hundred eighteen thousand, nine hundred eighty-one".