21995407 has 8 divisors (see below), whose sum is σ = 26460800. Its totient is φ = 17860824.

The previous prime is 21995401. The next prime is 21995419. The reversal of 21995407 is 70459912.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21995407 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 (21995401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82557 + ... + 82822.

It is an arithmetic number, because the mean of its divisors is an integer number (3307600).

Almost surely, 2^21995407 is an apocalyptic number.

21995407 is a deficient number, since it is larger than the sum of its proper divisors (4465393).

21995407 is a wasteful number, since it uses less digits than its factorization.

21995407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165405.

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

The square root of 21995407 is about 4689.9261188211. The cubic root of 21995407 is about 280.1844320620.

The spelling of 21995407 in words is "twenty-one million, nine hundred ninety-five thousand, four hundred seven".