21748307 has 12 divisors (see below), whose sum is σ = 25588440. Its totient is φ = 18428256.

The previous prime is 21748297. The next prime is 21748313. The reversal of 21748307 is 70384712.

It is a happy number.

It is not a de Polignac number, because 21748307 - 2¹⁰ = 21747283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21748367) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1868 + ... + 6854.

It is an arithmetic number, because the mean of its divisors is an integer number (2132370).

Almost surely, 2^21748307 is an apocalyptic number.

21748307 is a deficient number, since it is larger than the sum of its proper divisors (3840133).

21748307 is an equidigital number, since it uses as much as digits as its factorization.

21748307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5090 (or 5083 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 21748307 is about 4663.5080143600. The cubic root of 21748307 is about 279.1312657667.

The spelling of 21748307 in words is "twenty-one million, seven hundred forty-eight thousand, three hundred seven".