87994781 has 16 divisors (see below), whose sum is σ = 101952000. Its totient is φ = 74393088.

The previous prime is 87994759. The next prime is 87994801. The reversal of 87994781 is 18749978.

It is not a de Polignac number, because 87994781 - 2⁶ = 87994717 is a prime.

It is a super-2 number, since 2×87994781² = 15486162966475922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87994721) 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, 249101 + ... + 249453.

It is an arithmetic number, because the mean of its divisors is an integer number (6372000).

Almost surely, 2^87994781 is an apocalyptic number.

It is an amenable number.

87994781 is a deficient number, since it is larger than the sum of its proper divisors (13957219).

87994781 is a wasteful number, since it uses less digits than its factorization.

87994781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748.

The product of its digits is 1016064, while the sum is 53.

The square root of 87994781 is about 9380.5533418877. The cubic root of 87994781 is about 444.7872247945.

The spelling of 87994781 in words is "eighty-seven million, nine hundred ninety-four thousand, seven hundred eighty-one".