20400975 has 36 divisors (see below), whose sum is σ = 41763696. Its totient is φ = 9325440.

The previous prime is 20400967. The next prime is 20400997. The reversal of 20400975 is 57900402.

It is not a de Polignac number, because 20400975 - 2³ = 20400967 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4902 + ... + 8051.

Almost surely, 2^20400975 is an apocalyptic number.

20400975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20400975 is an abundant number, since it is smaller than the sum of its proper divisors (21362721).

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

20400975 is a wasteful number, since it uses less digits than its factorization.

20400975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12976 (or 12968 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 20400975 is about 4516.7438492790. The cubic root of 20400975 is about 273.2437946194.

The spelling of 20400975 in words is "twenty million, four hundred thousand, nine hundred seventy-five".