87981540 has 48 divisors (see below), whose sum is σ = 246809472. Its totient is φ = 23417856.

The previous prime is 87981539. The next prime is 87981541. The reversal of 87981540 is 4518978.

It is an interprime number because it is at equal distance from previous prime (87981539) and next prime (87981541).

It is a junction number, because it is equal to n+sod(n) for n = 87981492 and 87981501.

It is not an unprimeable number, because it can be changed into a prime (87981541) 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 15 ways as a sum of consecutive naturals, for example, 42612 + ... + 44628.

It is an arithmetic number, because the mean of its divisors is an integer number (5141864).

Almost surely, 2^87981540 is an apocalyptic number.

It is an amenable number.

87981540 is an abundant number, since it is smaller than the sum of its proper divisors (158827932).

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

87981540 is a wasteful number, since it uses less digits than its factorization.

87981540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756 (or 2754 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 87981540 is about 9379.8475467355. The cubic root of 87981540 is about 444.7649139142.

The spelling of 87981540 in words is "eighty-seven million, nine hundred eighty-one thousand, five hundred forty".