20451975 has 12 divisors (see below), whose sum is σ = 33814056. Its totient is φ = 10907680.

The previous prime is 20451973. The next prime is 20451979. The reversal of 20451975 is 57915402.

It is not a de Polignac number, because 20451975 - 2¹ = 20451973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20451973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136272 + ... + 136421.

It is an arithmetic number, because the mean of its divisors is an integer number (2817838).

Almost surely, 2^20451975 is an apocalyptic number.

20451975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20451975 is a deficient number, since it is larger than the sum of its proper divisors (13362081).

20451975 is a wasteful number, since it uses less digits than its factorization.

20451975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272706 (or 272701 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 20451975 is about 4522.3859852958. The cubic root of 20451975 is about 273.4712974278.

The spelling of 20451975 in words is "twenty million, four hundred fifty-one thousand, nine hundred seventy-five".