21576025 has 9 divisors (see below), whose sum is σ = 26783101. Its totient is φ = 17242240.

The previous prime is 21576011. The next prime is 21576059. The reversal of 21576025 is 52067512.

The square root of 21576025 is 4645.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 10843849 + 10732176 = 3293^2 + 3276^2 .

It is not a de Polignac number, because 21576025 - 2¹⁷ = 21444953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21575984 and 21576002.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22761 + ... + 23689.

Almost surely, 2^21576025 is an apocalyptic number.

21576025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21576025 is the 4645-th square number.

21576025 is the 2323-rd centered octagonal number.

It is an amenable number.

21576025 is a deficient number, since it is larger than the sum of its proper divisors (5207076).

21576025 is an frugal number, since it uses more digits than its factorization.

21576025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1868 (or 934 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The cubic root of 21576025 is about 278.3922528961.

The spelling of 21576025 in words is "twenty-one million, five hundred seventy-six thousand, twenty-five".