21477458 has 18 divisors (see below), whose sum is σ = 33663279. Its totient is φ = 10276672.

The previous prime is 21477439. The next prime is 21477461. The reversal of 21477458 is 85477412.

It can be written as a sum of positive squares in 5 ways, for example, as 528529 + 20948929 = 727^2 + 4577^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3277.

It is a super-2 number, since 2×21477458² = 922562404283528, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 190010 + ... + 190122.

Almost surely, 2^21477458 is an apocalyptic number.

21477458 is a deficient number, since it is larger than the sum of its proper divisors (12185821).

21477458 is an equidigital number, since it uses as much as digits as its factorization.

21477458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286 (or 144 counting only the distinct ones).

The product of its digits is 62720, while the sum is 38.

The square root of 21477458 is about 4634.3778438966. The cubic root of 21477458 is about 277.9676738977.

The spelling of 21477458 in words is "twenty-one million, four hundred seventy-seven thousand, four hundred fifty-eight".