87999978 has 64 divisors (see below), whose sum is σ = 207360000. Its totient is φ = 24615360.

The previous prime is 87999971. The next prime is 87999997.

87999978 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×87999978² = 15487992256000968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is not an unprimeable number, because it can be changed into a prime (87999971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43023 + ... + 45021.

It is an arithmetic number, because the mean of its divisors is an integer number (3240000).

Almost surely, 2^87999978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87999978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103680000).

87999978 is an abundant number, since it is smaller than the sum of its proper divisors (119360022).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

87999978 is a wasteful number, since it uses less digits than its factorization.

87999978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2067.

The product of its digits is 20575296, while the sum is 66.

The square root of 87999978 is about 9380.8303470428. The cubic root of 87999978 is about 444.7959810475.

The spelling of 87999978 in words is "eighty-seven million, nine hundred ninety-nine thousand, nine hundred seventy-eight".