21151456 has 12 divisors (see below), whose sum is σ = 41641992. Its totient is φ = 10575712.

The previous prime is 21151433. The next prime is 21151483. The reversal of 21151456 is 65415112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21151456.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330460 + ... + 330523.

It is an arithmetic number, because the mean of its divisors is an integer number (3470166).

Almost surely, 2^21151456 is an apocalyptic number.

It is an amenable number.

21151456 is a deficient number, since it is larger than the sum of its proper divisors (20490536).

21151456 is an equidigital number, since it uses as much as digits as its factorization.

21151456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660993 (or 660985 counting only the distinct ones).

The product of its digits is 1200, while the sum is 25.

The square root of 21151456 is about 4599.0712105815. The cubic root of 21151456 is about 276.5540923593.

Adding to 21151456 its reverse (65415112), we get a palindrome (86566568).

The spelling of 21151456 in words is "twenty-one million, one hundred fifty-one thousand, four hundred fifty-six".