21375057 has 32 divisors (see below), whose sum is σ = 33246720. Its totient is φ = 12078720.

The previous prime is 21375049. The next prime is 21375061. The reversal of 21375057 is 75057312.

21375057 is nontrivially palindromic in base 8.

It is not a de Polignac number, because 21375057 - 2³ = 21375049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21375007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 45538 + ... + 46004.

It is an arithmetic number, because the mean of its divisors is an integer number (1038960).

Almost surely, 2^21375057 is an apocalyptic number.

It is an amenable number.

21375057 is a deficient number, since it is larger than the sum of its proper divisors (11871663).

21375057 is a wasteful number, since it uses less digits than its factorization.

21375057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 573.

The product of its (nonzero) digits is 7350, while the sum is 30.

The square root of 21375057 is about 4623.3166666366. The cubic root of 21375057 is about 277.5252018342.

The spelling of 21375057 in words is "twenty-one million, three hundred seventy-five thousand, fifty-seven".