21458719 has 2 divisors, whose sum is σ = 21458720. Its totient is φ = 21458718.

The previous prime is 21458707. The next prime is 21458741. The reversal of 21458719 is 91785412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21458719 - 2⁹ = 21458207 is a prime.

It is a super-2 number, since 2×21458719² = 920953242241922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21458119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10729359 + 10729360.

It is an arithmetic number, because the mean of its divisors is an integer number (10729360).

Almost surely, 2^21458719 is an apocalyptic number.

21458719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21458719 is an equidigital number, since it uses as much as digits as its factorization.

21458719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 21458719 is about 4632.3556642382. The cubic root of 21458719 is about 277.8868084639.

The spelling of 21458719 in words is "twenty-one million, four hundred fifty-eight thousand, seven hundred nineteen".