21254553 has 12 divisors (see below), whose sum is σ = 32036160. Its totient is φ = 13553496.

The previous prime is 21254491. The next prime is 21254567. The reversal of 21254553 is 35545212.

It is a happy number.

It is not a de Polignac number, because 21254553 - 2⁸ = 21254297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21250553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51133 + ... + 51546.

It is an arithmetic number, because the mean of its divisors is an integer number (2669680).

Almost surely, 2^21254553 is an apocalyptic number.

21254553 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21254553 is a deficient number, since it is larger than the sum of its proper divisors (10781607).

21254553 is a wasteful number, since it uses less digits than its factorization.

21254553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102708 (or 102705 counting only the distinct ones).

The product of its digits is 6000, while the sum is 27.

The square root of 21254553 is about 4610.2660443840. The cubic root of 21254553 is about 277.0026934361.

Adding to 21254553 its reverse (35545212), we get a palindrome (56799765).

The spelling of 21254553 in words is "twenty-one million, two hundred fifty-four thousand, five hundred fifty-three".