21995307 has 20 divisors (see below), whose sum is σ = 32989440. Its totient is φ = 14604624.

The previous prime is 21995299. The next prime is 21995339. The reversal of 21995307 is 70359912.

It is not a de Polignac number, because 21995307 - 2³ = 21995299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21995387) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 30669 + ... + 31377.

It is an arithmetic number, because the mean of its divisors is an integer number (1649472).

Almost surely, 2^21995307 is an apocalyptic number.

21995307 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21995307 is a deficient number, since it is larger than the sum of its proper divisors (10994133).

21995307 is an equidigital number, since it uses as much as digits as its factorization.

21995307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1104 (or 1095 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 36.

The square root of 21995307 is about 4689.9154576602. The cubic root of 21995307 is about 280.1840074508.

The spelling of 21995307 in words is "twenty-one million, nine hundred ninety-five thousand, three hundred seven".