23570821 has 2 divisors, whose sum is σ = 23570822. Its totient is φ = 23570820.

The previous prime is 23570809. The next prime is 23570831. The reversal of 23570821 is 12807532.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18792225 + 4778596 = 4335^2 + 2186^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23570821 is a prime.

It is a super-2 number, since 2×23570821² = 1111167205228082, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 23570821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23570831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11785410 + 11785411.

It is an arithmetic number, because the mean of its divisors is an integer number (11785411).

Almost surely, 2^23570821 is an apocalyptic number.

It is an amenable number.

23570821 is a deficient number, since it is larger than the sum of its proper divisors (1).

23570821 is an equidigital number, since it uses as much as digits as its factorization.

23570821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 23570821 is about 4854.9789906857. The cubic root of 23570821 is about 286.7201641339.

The spelling of 23570821 in words is "twenty-three million, five hundred seventy thousand, eight hundred twenty-one".