20392640 has 28 divisors (see below), whose sum is σ = 48560736. Its totient is φ = 8156928.

The previous prime is 20392627. The next prime is 20392657. The reversal of 20392640 is 4629302.

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 3 ways as a sum of consecutive naturals, for example, 31544 + ... + 32183.

It is an arithmetic number, because the mean of its divisors is an integer number (1734312).

Almost surely, 2^20392640 is an apocalyptic number.

20392640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20392640 is an abundant number, since it is smaller than the sum of its proper divisors (28168096).

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

20392640 is an equidigital number, since it uses as much as digits as its factorization.

20392640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63744 (or 63734 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 20392640 is about 4515.8210770579. The cubic root of 20392640 is about 273.2065774887.

The spelling of 20392640 in words is "twenty million, three hundred ninety-two thousand, six hundred forty".