21494925 has 36 divisors (see below), whose sum is σ = 38997504. Its totient is φ = 11316000.

The previous prime is 21494917. The next prime is 21494929. The reversal of 21494925 is 52949412.

It is not a de Polignac number, because 21494925 - 2³ = 21494917 is a prime.

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

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 21494925.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21494929) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18100 + ... + 19250.

It is an arithmetic number, because the mean of its divisors is an integer number (1083264).

Almost surely, 2^21494925 is an apocalyptic number.

21494925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21494925 is a deficient number, since it is larger than the sum of its proper divisors (17502579).

21494925 is a wasteful number, since it uses less digits than its factorization.

21494925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250 (or 1242 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21494925 is about 4636.2619641258. The cubic root of 21494925 is about 278.0430078554.

The spelling of 21494925 in words is "twenty-one million, four hundred ninety-four thousand, nine hundred twenty-five".