87989820 has 48 divisors (see below), whose sum is σ = 249758880. Its totient is φ = 23141376.

The previous prime is 87989819. The next prime is 87989821. The reversal of 87989820 is 2898978.

It is an interprime number because it is at equal distance from previous prime (87989819) and next prime (87989821).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87989821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5665 + ... + 14424.

It is an arithmetic number, because the mean of its divisors is an integer number (5203310).

Almost surely, 2^87989820 is an apocalyptic number.

It is an amenable number.

87989820 is an abundant number, since it is smaller than the sum of its proper divisors (161769060).

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

87989820 is a wasteful number, since it uses less digits than its factorization.

87989820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20174 (or 20172 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 51.

The square root of 87989820 is about 9380.2889081307. The cubic root of 87989820 is about 444.7788658484.

The spelling of 87989820 in words is "eighty-seven million, nine hundred eighty-nine thousand, eight hundred twenty".