28573621 has 2 divisors, whose sum is σ = 28573622. Its totient is φ = 28573620.

The previous prime is 28573553. The next prime is 28573627. The reversal of 28573621 is 12637582.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19483396 + 9090225 = 4414^2 + 3015^2 .

It is a cyclic number.

It is not a de Polignac number, because 28573621 - 2²¹ = 26476469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28573627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14286810 + 14286811.

It is an arithmetic number, because the mean of its divisors is an integer number (14286811).

Almost surely, 2^28573621 is an apocalyptic number.

It is an amenable number.

28573621 is a deficient number, since it is larger than the sum of its proper divisors (1).

28573621 is an equidigital number, since it uses as much as digits as its factorization.

28573621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 34.

The square root of 28573621 is about 5345.4299172284. The cubic root of 28573621 is about 305.7185281033.

The spelling of 28573621 in words is "twenty-eight million, five hundred seventy-three thousand, six hundred twenty-one".