21236925 has 12 divisors (see below), whose sum is σ = 35111840. Its totient is φ = 11326320.

The previous prime is 21236921. The next prime is 21236947. The reversal of 21236925 is 52963212.

It is not a de Polignac number, because 21236925 - 2² = 21236921 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21236892 and 21236901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21236921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141505 + ... + 141654.

Almost surely, 2^21236925 is an apocalyptic number.

21236925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21236925 is a deficient number, since it is larger than the sum of its proper divisors (13874915).

21236925 is a wasteful number, since it uses less digits than its factorization.

21236925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283172 (or 283167 counting only the distinct ones).

The product of its digits is 6480, while the sum is 30.

The square root of 21236925 is about 4608.3538275614. The cubic root of 21236925 is about 276.9260925301.

The spelling of 21236925 in words is "twenty-one million, two hundred thirty-six thousand, nine hundred twenty-five".