21058057 has 2 divisors, whose sum is σ = 21058058. Its totient is φ = 21058056.

The previous prime is 21058049. The next prime is 21058067. The reversal of 21058057 is 75085012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19044496 + 2013561 = 4364^2 + 1419^2 .

It is a cyclic number.

It is not a de Polignac number, because 21058057 - 2³ = 21058049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21058027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10529028 + 10529029.

It is an arithmetic number, because the mean of its divisors is an integer number (10529029).

Almost surely, 2^21058057 is an apocalyptic number.

It is an amenable number.

21058057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21058057 is an equidigital number, since it uses as much as digits as its factorization.

21058057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 21058057 is about 4588.9058608780. The cubic root of 21058057 is about 276.1464295107.

The spelling of 21058057 in words is "twenty-one million, fifty-eight thousand, fifty-seven".