20435640 has 64 divisors (see below), whose sum is σ = 64540800. Its totient is φ = 5162112.

The previous prime is 20435629. The next prime is 20435651. The reversal of 20435640 is 4653402.

It is an interprime number because it is at equal distance from previous prime (20435629) and next prime (20435651).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20435640.

It is a congruent number.

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, 2202 + ... + 6761.

It is an arithmetic number, because the mean of its divisors is an integer number (1008450).

Almost surely, 2^20435640 is an apocalyptic number.

20435640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20435640 is an abundant number, since it is smaller than the sum of its proper divisors (44105160).

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

20435640 is a wasteful number, since it uses less digits than its factorization.

20435640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8996 (or 8992 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 24.

The square root of 20435640 is about 4520.5796088555. The cubic root of 20435640 is about 273.3984708267.

The spelling of 20435640 in words is "twenty million, four hundred thirty-five thousand, six hundred forty".