87731550 has 144 divisors (see below), whose sum is σ = 256888320. Its totient is φ = 21384000.

The previous prime is 87731549. The next prime is 87731557. The reversal of 87731550 is 5513778.

87731550 is a `hidden beast` number, since 8 + 77 + 31 + 550 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87731557) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 264885 + ... + 265215.

Almost surely, 2^87731550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87731550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128444160).

87731550 is an abundant number, since it is smaller than the sum of its proper divisors (169156770).

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

87731550 is a wasteful number, since it uses less digits than its factorization.

87731550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399 (or 391 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 87731550 is about 9366.5121576817. The cubic root of 87731550 is about 444.3432638887.

The spelling of 87731550 in words is "eighty-seven million, seven hundred thirty-one thousand, five hundred fifty".