21172583 has 2 divisors, whose sum is σ = 21172584. Its totient is φ = 21172582.

The previous prime is 21172579. The next prime is 21172601. The reversal of 21172583 is 38527112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21172583 - 2² = 21172579 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21172483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10586291 + 10586292.

It is an arithmetic number, because the mean of its divisors is an integer number (10586292).

Almost surely, 2^21172583 is an apocalyptic number.

21172583 is a deficient number, since it is larger than the sum of its proper divisors (1).

21172583 is an equidigital number, since it uses as much as digits as its factorization.

21172583 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 29.

The square root of 21172583 is about 4601.3675141201. The cubic root of 21172583 is about 276.6461398296.

Adding to 21172583 its reverse (38527112), we get a palindrome (59699695).

The spelling of 21172583 in words is "twenty-one million, one hundred seventy-two thousand, five hundred eighty-three".