21054501 has 12 divisors (see below), whose sum is σ = 32751628. Its totient is φ = 12956544.

The previous prime is 21054457. The next prime is 21054521. The reversal of 21054501 is 10545012.

21054501 is a `hidden beast` number, since 210 + 5 + 450 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13068225 + 7986276 = 3615^2 + 2826^2 .

It is not a de Polignac number, because 21054501 - 2⁶ = 21054437 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

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 11 ways as a sum of consecutive naturals, for example, 89860 + ... + 90093.

Almost surely, 2^21054501 is an apocalyptic number.

It is an amenable number.

21054501 is a deficient number, since it is larger than the sum of its proper divisors (11697127).

21054501 is a wasteful number, since it uses less digits than its factorization.

21054501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179972 (or 179969 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 21054501 is about 4588.5183883254. The cubic root of 21054501 is about 276.1308846770.

Adding to 21054501 its reverse (10545012), we get a palindrome (31599513).

The spelling of 21054501 in words is "twenty-one million, fifty-four thousand, five hundred one".