99840428 has 12 divisors (see below), whose sum is σ = 174848520. Its totient is φ = 49883712.

The previous prime is 99840409. The next prime is 99840443. The reversal of 99840428 is 82404899.

It is a happy number.

It is a super-2 number, since 2×99840428² = 19936222126446368, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2426 + ... + 14337.

It is an arithmetic number, because the mean of its divisors is an integer number (14570710).

Almost surely, 2^99840428 is an apocalyptic number.

It is an amenable number.

99840428 is a deficient number, since it is larger than the sum of its proper divisors (75008092).

99840428 is a wasteful number, since it uses less digits than its factorization.

99840428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18256 (or 18254 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 99840428 is about 9992.0182145551. The cubic root of 99840428 is about 463.9118627183.

The spelling of 99840428 in words is "ninety-nine million, eight hundred forty thousand, four hundred twenty-eight".