21526225 has 12 divisors (see below), whose sum is σ = 30505984. Its totient is φ = 14760720.

The previous prime is 21526213. The next prime is 21526237. The reversal of 21526225 is 52262512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21526213) and next prime (21526237).

It is not a de Polignac number, because 21526225 - 2¹³ = 21518033 is a prime.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21526225.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61329 + ... + 61678.

Almost surely, 2^21526225 is an apocalyptic number.

21526225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21526225 is a deficient number, since it is larger than the sum of its proper divisors (8979759).

21526225 is a wasteful number, since it uses less digits than its factorization.

21526225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123024 (or 123019 counting only the distinct ones).

The product of its digits is 2400, while the sum is 25.

The square root of 21526225 is about 4639.6363004011. The cubic root of 21526225 is about 278.1779005548.

Adding to 21526225 its reverse (52262512), we get a palindrome (73788737).

The spelling of 21526225 in words is "twenty-one million, five hundred twenty-six thousand, two hundred twenty-five".