21654359 has 2 divisors, whose sum is σ = 21654360. Its totient is φ = 21654358.

The previous prime is 21654317. The next prime is 21654371. The reversal of 21654359 is 95345612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21654359 - 2⁸ = 21654103 is a prime.

It is a super-2 number, since 2×21654359² = 937822527401762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21654559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827179 + 10827180.

It is an arithmetic number, because the mean of its divisors is an integer number (10827180).

Almost surely, 2^21654359 is an apocalyptic number.

21654359 is a deficient number, since it is larger than the sum of its proper divisors (1).

21654359 is an equidigital number, since it uses as much as digits as its factorization.

21654359 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32400, while the sum is 35.

The square root of 21654359 is about 4653.4244379811. The cubic root of 21654359 is about 278.7287566509.

The spelling of 21654359 in words is "twenty-one million, six hundred fifty-four thousand, three hundred fifty-nine".