21248907 has 8 divisors (see below), whose sum is σ = 28445760. Its totient is φ = 14109000.

The previous prime is 21248893. The next prime is 21248921. The reversal of 21248907 is 70984212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21248893) and next prime (21248921).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21248907 - 2⁷ = 21248779 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21248957) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13357 + ... + 14862.

It is an arithmetic number, because the mean of its divisors is an integer number (3555720).

Almost surely, 2^21248907 is an apocalyptic number.

21248907 is a deficient number, since it is larger than the sum of its proper divisors (7196853).

21248907 is a wasteful number, since it uses less digits than its factorization.

21248907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28473.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21248907 is about 4609.6536746268. The cubic root of 21248907 is about 276.9781638571.

It can be divided in two parts, 21248 and 907, that added together give a triangular number (22155 = T₂₁₀).

The spelling of 21248907 in words is "twenty-one million, two hundred forty-eight thousand, nine hundred seven".