87940840 has 48 divisors (see below), whose sum is σ = 214274700. Its totient is φ = 32467968.

The previous prime is 87940819. The next prime is 87940849. The reversal of 87940840 is 4804978.

It can be written as a sum of positive squares in 6 ways, for example, as 2304324 + 85636516 = 1518^2 + 9254^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 87940793 and 87940802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87940849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 256 + ... + 13264.

Almost surely, 2^87940840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87940840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107137350).

87940840 is an abundant number, since it is smaller than the sum of its proper divisors (126333860).

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

87940840 is a wasteful number, since it uses less digits than its factorization.

87940840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13046 (or 13029 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 87940840 is about 9377.6777509147. The cubic root of 87940840 is about 444.6963210253.

The spelling of 87940840 in words is "eighty-seven million, nine hundred forty thousand, eight hundred forty".