21990707 has 8 divisors (see below), whose sum is σ = 23724576. Its totient is φ = 20305792.

The previous prime is 21990701. The next prime is 21990713. The reversal of 21990707 is 70709912.

It is an interprime number because it is at equal distance from previous prime (21990701) and next prime (21990713).

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

It is a cyclic number.

It is not a de Polignac number, because 21990707 - 2⁶ = 21990643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21990701) 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, 11303 + ... + 13104.

It is an arithmetic number, because the mean of its divisors is an integer number (2965572).

Almost surely, 2^21990707 is an apocalyptic number.

21990707 is a deficient number, since it is larger than the sum of its proper divisors (1733869).

21990707 is a wasteful number, since it uses less digits than its factorization.

21990707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24477.

The product of its (nonzero) digits is 7938, while the sum is 35.

The square root of 21990707 is about 4689.4250180593. The cubic root of 21990707 is about 280.1644739462.

The spelling of 21990707 in words is "twenty-one million, nine hundred ninety thousand, seven hundred seven".