21793459 has 2 divisors, whose sum is σ = 21793460. Its totient is φ = 21793458.

The previous prime is 21793451. The next prime is 21793463. The reversal of 21793459 is 95439712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21793459 - 2³ = 21793451 is a prime.

It is not a weakly prime, because it can be changed into another prime (21793451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10896729 + 10896730.

It is an arithmetic number, because the mean of its divisors is an integer number (10896730).

Almost surely, 2^21793459 is an apocalyptic number.

21793459 is a deficient number, since it is larger than the sum of its proper divisors (1).

21793459 is an equidigital number, since it uses as much as digits as its factorization.

21793459 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 40.

The square root of 21793459 is about 4668.3464952807. The cubic root of 21793459 is about 279.3243018341.

The spelling of 21793459 in words is "twenty-one million, seven hundred ninety-three thousand, four hundred fifty-nine".