99661580 has 12 divisors (see below), whose sum is σ = 209289360. Its totient is φ = 39864624.

The previous prime is 99661567. The next prime is 99661589. The reversal of 99661580 is 8516699.

It is not an unprimeable number, because it can be changed into a prime (99661589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2491520 + ... + 2491559.

It is an arithmetic number, because the mean of its divisors is an integer number (17440780).

Almost surely, 2^99661580 is an apocalyptic number.

It is an amenable number.

99661580 is an abundant number, since it is smaller than the sum of its proper divisors (109627780).

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

99661580 is a wasteful number, since it uses less digits than its factorization.

99661580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4983088 (or 4983086 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 99661580 is about 9983.0646597125. The cubic root of 99661580 is about 463.6346894258.

The spelling of 99661580 in words is "ninety-nine million, six hundred sixty-one thousand, five hundred eighty".