20633640 has 32 divisors (see below), whose sum is σ = 61901280. Its totient is φ = 5502272.

The previous prime is 20633633. The next prime is 20633651. The reversal of 20633640 is 4633602.

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 20633640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85854 + ... + 86093.

It is an arithmetic number, because the mean of its divisors is an integer number (1934415).

Almost surely, 2^20633640 is an apocalyptic number.

20633640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20633640 is an abundant number, since it is smaller than the sum of its proper divisors (41267640).

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

20633640 is a wasteful number, since it uses less digits than its factorization.

20633640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171961 (or 171957 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 24.

The square root of 20633640 is about 4542.4266642402. The cubic root of 20633640 is about 274.2786161978.

The spelling of 20633640 in words is "twenty million, six hundred thirty-three thousand, six hundred forty".