21052725 has 12 divisors (see below), whose sum is σ = 34807296. Its totient is φ = 11228080.

The previous prime is 21052711. The next prime is 21052729. The reversal of 21052725 is 52725012.

It is not a de Polignac number, because 21052725 - 2⁴ = 21052709 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 21052695 and 21052704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052729) 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, 140277 + ... + 140426.

It is an arithmetic number, because the mean of its divisors is an integer number (2900608).

Almost surely, 2^21052725 is an apocalyptic number.

21052725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21052725 is a deficient number, since it is larger than the sum of its proper divisors (13754571).

21052725 is a wasteful number, since it uses less digits than its factorization.

21052725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280716 (or 280711 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 21052725 is about 4588.3248577231. The cubic root of 21052725 is about 276.1231203476.

Adding to 21052725 its reverse (52725012), we get a palindrome (73777737).

The spelling of 21052725 in words is "twenty-one million, fifty-two thousand, seven hundred twenty-five".