21022725 has 12 divisors (see below), whose sum is σ = 34757696. Its totient is φ = 11212080.

The previous prime is 21022723. The next prime is 21022733. The reversal of 21022725 is 52722012.

It is a happy number.

It is not a de Polignac number, because 21022725 - 2¹ = 21022723 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140077 + ... + 140226.

Almost surely, 2^21022725 is an apocalyptic number.

21022725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21022725 is a deficient number, since it is larger than the sum of its proper divisors (13734971).

21022725 is a wasteful number, since it uses less digits than its factorization.

21022725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280316 (or 280311 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21022725 is about 4585.0545253028. The cubic root of 21022725 is about 275.9919000984.

Adding to 21022725 its reverse (52722012), we get a palindrome (73744737).

The spelling of 21022725 in words is "twenty-one million, twenty-two thousand, seven hundred twenty-five".