21229975 has 12 divisors (see below), whose sum is σ = 28350616. Its totient is φ = 15677280.

The previous prime is 21229961. The next prime is 21229979. The reversal of 21229975 is 57992212.

It is not a de Polignac number, because 21229975 - 2⁷ = 21229847 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 (21229979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32337 + ... + 32986.

Almost surely, 2^21229975 is an apocalyptic number.

21229975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21229975 is a deficient number, since it is larger than the sum of its proper divisors (7120641).

21229975 is a wasteful number, since it uses less digits than its factorization.

21229975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65346 (or 65341 counting only the distinct ones).

The product of its digits is 22680, while the sum is 37.

The square root of 21229975 is about 4607.5997004948. The cubic root of 21229975 is about 276.8958802727.

The spelling of 21229975 in words is "twenty-one million, two hundred twenty-nine thousand, nine hundred seventy-five".