87891790 has 48 divisors (see below), whose sum is σ = 185238144. Its totient is φ = 29937600.

The previous prime is 87891767. The next prime is 87891799. The reversal of 87891790 is 9719878.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87891799) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88195 + ... + 89185.

It is an arithmetic number, because the mean of its divisors is an integer number (3859128).

Almost surely, 2^87891790 is an apocalyptic number.

87891790 is an abundant number, since it is smaller than the sum of its proper divisors (97346354).

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

87891790 is a wasteful number, since it uses less digits than its factorization.

87891790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193 (or 1186 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 87891790 is about 9375.0621331274. The cubic root of 87891790 is about 444.6136275116.

The spelling of 87891790 in words is "eighty-seven million, eight hundred ninety-one thousand, seven hundred ninety".