21104307 has 48 divisors (see below), whose sum is σ = 38088960. Its totient is φ = 11407392.

The previous prime is 21104287. The next prime is 21104311. The reversal of 21104307 is 70340112.

It is not a de Polignac number, because 21104307 - 2⁶ = 21104243 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21104307.

It is not an unprimeable number, because it can be changed into a prime (21104407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31993 + ... + 32645.

It is an arithmetic number, because the mean of its divisors is an integer number (793520).

Almost surely, 2^21104307 is an apocalyptic number.

21104307 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21104307 is a deficient number, since it is larger than the sum of its proper divisors (16984653).

21104307 is an equidigital number, since it uses as much as digits as its factorization.

21104307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694 (or 682 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21104307 is about 4593.9424245413. The cubic root of 21104307 is about 276.3484493125.

Adding to 21104307 its reverse (70340112), we get a palindrome (91444419).

The spelling of 21104307 in words is "twenty-one million, one hundred four thousand, three hundred seven".