87640722 has 48 divisors (see below), whose sum is σ = 205267608. Its totient is φ = 26864640.

The previous prime is 87640717. The next prime is 87640723. The reversal of 87640722 is 22704678.

87640722 is a `hidden beast` number, since 8 + 7 + 640 + 7 + 2 + 2 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 63345681 + 24295041 = 7959^2 + 4929^2 .

It is not an unprimeable number, because it can be changed into a prime (87640723) 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, 82072 + ... + 83132.

Almost surely, 2^87640722 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87640722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102633804).

87640722 is an abundant number, since it is smaller than the sum of its proper divisors (117626886).

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

87640722 is a wasteful number, since it uses less digits than its factorization.

87640722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1435 (or 1432 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 87640722 is about 9361.6623523817. The cubic root of 87640722 is about 444.1898688795.

The spelling of 87640722 in words is "eighty-seven million, six hundred forty thousand, seven hundred twenty-two".