99640025 has 24 divisors (see below), whose sum is σ = 129902400. Its totient is φ = 75669440.

The previous prime is 99640019. The next prime is 99640031. The reversal of 99640025 is 52004699.

It is an interprime number because it is at equal distance from previous prime (99640019) and next prime (99640031).

It is a de Polignac number, because none of the positive numbers 2^k-99640025 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85094 + ... + 86256.

It is an arithmetic number, because the mean of its divisors is an integer number (5412600).

Almost surely, 2^99640025 is an apocalyptic number.

It is an amenable number.

99640025 is a deficient number, since it is larger than the sum of its proper divisors (30262375).

99640025 is a wasteful number, since it uses less digits than its factorization.

99640025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1345 (or 1340 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 99640025 is about 9981.9850230302. The cubic root of 99640025 is about 463.6012617455.

The spelling of 99640025 in words is "ninety-nine million, six hundred forty thousand, twenty-five".