87920640 has 260 divisors, whose sum is σ = 321119964. Its totient is φ = 23003136.

The previous prime is 87920639. The next prime is 87920641. The reversal of 87920640 is 4602978.

87920640 is a `hidden beast` number, since 8 + 7 + 9 + 2 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (87920639) and next prime (87920641).

It can be written as a sum of positive squares in 2 ways, for example, as 47775744 + 40144896 = 6912^2 + 6336^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 87920595 and 87920604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87920641) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1658854 + ... + 1658906.

Almost surely, 2^87920640 is an apocalyptic number.

87920640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87920640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160559982).

87920640 is an abundant number, since it is smaller than the sum of its proper divisors (233199324).

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

87920640 is an equidigital number, since it uses as much as digits as its factorization.

87920640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 63 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 87920640 is about 9376.6006633534. The cubic root of 87920640 is about 444.6622695214.

The spelling of 87920640 in words is "eighty-seven million, nine hundred twenty thousand, six hundred forty".