21357053 has 2 divisors, whose sum is σ = 21357054. Its totient is φ = 21357052.

The previous prime is 21357043. The next prime is 21357059. The reversal of 21357053 is 35075312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21279769 + 77284 = 4613^2 + 278^2 .

It is a cyclic number.

It is not a de Polignac number, because 21357053 - 2⁶ = 21356989 is a prime.

It is a super-2 number, since 2×21357053² = 912247425689618, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21357059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678526 + 10678527.

It is an arithmetic number, because the mean of its divisors is an integer number (10678527).

Almost surely, 2^21357053 is an apocalyptic number.

It is an amenable number.

21357053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357053 is an equidigital number, since it uses as much as digits as its factorization.

21357053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3150, while the sum is 26.

The square root of 21357053 is about 4621.3691694129. The cubic root of 21357053 is about 277.4472610324.

The spelling of 21357053 in words is "twenty-one million, three hundred fifty-seven thousand, fifty-three".