87249780 has 72 divisors (see below), whose sum is σ = 280235592. Its totient is φ = 21897216.

The previous prime is 87249751. The next prime is 87249793. The reversal of 87249780 is 8794278.

87249780 is a `hidden beast` number, since 87 + 2 + 497 + 80 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 41525136 + 45724644 = 6444^2 + 6762^2 .

It is a super-2 number, since 2×87249780² = 15225048220096800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11197 + ... + 17316.

It is an arithmetic number, because the mean of its divisors is an integer number (3892161).

Almost surely, 2^87249780 is an apocalyptic number.

It is an amenable number.

87249780 is an abundant number, since it is smaller than the sum of its proper divisors (192985812).

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

87249780 is a wasteful number, since it uses less digits than its factorization.

87249780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28545 (or 28540 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The square root of 87249780 is about 9340.7590697973. The cubic root of 87249780 is about 443.5284133392.

The spelling of 87249780 in words is "eighty-seven million, two hundred forty-nine thousand, seven hundred eighty".