99640420 has 48 divisors (see below), whose sum is σ = 229154688. Its totient is φ = 36092160.

The previous prime is 99640403. The next prime is 99640441. The reversal of 99640420 is 2404699.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68137 + ... + 69583.

It is an arithmetic number, because the mean of its divisors is an integer number (4774056).

Almost surely, 2^99640420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99640420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114577344).

99640420 is an abundant number, since it is smaller than the sum of its proper divisors (129514268).

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

99640420 is a wasteful number, since it uses less digits than its factorization.

99640420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780 (or 1778 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 99640420 is about 9982.0048086544. The cubic root of 99640420 is about 463.6018743582.

The spelling of 99640420 in words is "ninety-nine million, six hundred forty thousand, four hundred twenty".