21601456 has 20 divisors (see below), whose sum is σ = 42134704. Its totient is φ = 10728000.

The previous prime is 21601453. The next prime is 21601471. The reversal of 21601456 is 65410612.

It is a self number, because there is not a number n which added to its sum of digits gives 21601456.

It is not an unprimeable number, because it can be changed into a prime (21601453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2055 + ... + 6886.

Almost surely, 2^21601456 is an apocalyptic number.

It is an amenable number.

21601456 is a deficient number, since it is larger than the sum of its proper divisors (20533248).

21601456 is a wasteful number, since it uses less digits than its factorization.

21601456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9100 (or 9094 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21601456 is about 4647.7366534691. The cubic root of 21601456 is about 278.5015874256.

The spelling of 21601456 in words is "twenty-one million, six hundred one thousand, four hundred fifty-six".