21339025 has 12 divisors (see below), whose sum is σ = 26720512. Its totient is φ = 16903440.

The previous prime is 21339023. The next prime is 21339037. The reversal of 21339025 is 52093312.

It is a happy number.

It is not a de Polignac number, because 21339025 - 2¹ = 21339023 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21339023) 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, 1569 + ... + 6718.

Almost surely, 2^21339025 is an apocalyptic number.

21339025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21339025 is a deficient number, since it is larger than the sum of its proper divisors (5381487).

21339025 is a wasteful number, since it uses less digits than its factorization.

21339025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8400 (or 8395 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 21339025 is about 4619.4182534168. The cubic root of 21339025 is about 277.3691724299.

The spelling of 21339025 in words is "twenty-one million, three hundred thirty-nine thousand, twenty-five".