21992907 has 8 divisors (see below), whose sum is σ = 29626576. Its totient is φ = 14510592.

The previous prime is 21992897. The next prime is 21992923. The reversal of 21992907 is 70929912.

It is a happy number.

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

It is not a de Polignac number, because 21992907 - 2⁶ = 21992843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21992947) 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, 37498 + ... + 38079.

It is an arithmetic number, because the mean of its divisors is an integer number (3703322).

Almost surely, 2^21992907 is an apocalyptic number.

21992907 is a deficient number, since it is larger than the sum of its proper divisors (7633669).

21992907 is an equidigital number, since it uses as much as digits as its factorization.

21992907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75677.

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 21992907 is about 4689.6595825284. The cubic root of 21992907 is about 280.1738163969.

The spelling of 21992907 in words is "twenty-one million, nine hundred ninety-two thousand, nine hundred seven".