21961625 has 32 divisors (see below), whose sum is σ = 32997120. Its totient is φ = 14256000.

The previous prime is 21961601. The next prime is 21961627. The reversal of 21961625 is 52616912.

It is a happy number.

It is not a de Polignac number, because 21961625 - 2⁶ = 21961561 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21961591 and 21961600.

It is not an unprimeable number, because it can be changed into a prime (21961627) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15965 + ... + 17285.

It is an arithmetic number, because the mean of its divisors is an integer number (1031160).

Almost surely, 2^21961625 is an apocalyptic number.

21961625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21961625 is a deficient number, since it is larger than the sum of its proper divisors (11035495).

21961625 is a wasteful number, since it uses less digits than its factorization.

21961625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1362 (or 1352 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 21961625 is about 4686.3231856115. The cubic root of 21961625 is about 280.0409166396.

The spelling of 21961625 in words is "twenty-one million, nine hundred sixty-one thousand, six hundred twenty-five".