21594057 has 16 divisors (see below), whose sum is σ = 29424768. Its totient is φ = 14083200.

The previous prime is 21594049. The next prime is 21594071. The reversal of 21594057 is 75049512.

It is not a de Polignac number, because 21594057 - 2³ = 21594049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21594047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32743 + ... + 33395.

It is an arithmetic number, because the mean of its divisors is an integer number (1839048).

Almost surely, 2^21594057 is an apocalyptic number.

It is an amenable number.

21594057 is a deficient number, since it is larger than the sum of its proper divisors (7830711).

21594057 is a wasteful number, since it uses less digits than its factorization.

21594057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880.

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

The square root of 21594057 is about 4646.9406064636. The cubic root of 21594057 is about 278.4697860420.

It can be divided in two parts, 2159 and 4057, that added together give a triangular number (6216 = T₁₁₁).

The spelling of 21594057 in words is "twenty-one million, five hundred ninety-four thousand, fifty-seven".