21054520 has 32 divisors (see below), whose sum is σ = 48478320. Its totient is φ = 8225280.

The previous prime is 21054457. The next prime is 21054521. The reversal of 21054520 is 2545012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4401 + ... + 7840.

Almost surely, 2^21054520 is an apocalyptic number.

21054520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21054520 is an abundant number, since it is smaller than the sum of its proper divisors (27423800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21054520 is a wasteful number, since it uses less digits than its factorization.

21054520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12295 (or 12291 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21054520 is about 4588.5204587100. The cubic root of 21054520 is about 276.1309677389.

Adding to 21054520 its reverse (2545012), we get a palindrome (23599532).

The spelling of 21054520 in words is "twenty-one million, fifty-four thousand, five hundred twenty".