21910925 has 12 divisors (see below), whose sum is σ = 27426816. Its totient is φ = 17362800.

The previous prime is 21910891. The next prime is 21910937. The reversal of 21910925 is 52901912.

It is a de Polignac number, because none of the positive numbers 2^k-21910925 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1421 + ... + 6770.

It is an arithmetic number, because the mean of its divisors is an integer number (2285568).

Almost surely, 2^21910925 is an apocalyptic number.

21910925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21910925 is a deficient number, since it is larger than the sum of its proper divisors (5515891).

21910925 is a wasteful number, since it uses less digits than its factorization.

21910925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8308 (or 8303 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 21910925 is about 4680.9107019895. The cubic root of 21910925 is about 279.8252523575.

The spelling of 21910925 in words is "twenty-one million, nine hundred ten thousand, nine hundred twenty-five".