21454857 has 24 divisors (see below), whose sum is σ = 33512960. Its totient is φ = 13180320.

The previous prime is 21454841. The next prime is 21454871. The reversal of 21454857 is 75845412.

It is not a de Polignac number, because 21454857 - 2⁴ = 21454841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21454817) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4632 + ... + 8022.

Almost surely, 2^21454857 is an apocalyptic number.

It is an amenable number.

21454857 is a deficient number, since it is larger than the sum of its proper divisors (12058103).

21454857 is a wasteful number, since it uses less digits than its factorization.

21454857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3453 (or 3450 counting only the distinct ones).

The product of its digits is 44800, while the sum is 36.

The square root of 21454857 is about 4631.9387949324. The cubic root of 21454857 is about 277.8701367132.

The spelling of 21454857 in words is "twenty-one million, four hundred fifty-four thousand, eight hundred fifty-seven".