21760313 has 4 divisors (see below), whose sum is σ = 22035840. Its totient is φ = 21484788.

The previous prime is 21760309. The next prime is 21760331. The reversal of 21760313 is 31306712.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21760313 - 2² = 21760309 is a prime.

It is a super-2 number, since 2×21760313² = 947022443715938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21760303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137645 + ... + 137802.

It is an arithmetic number, because the mean of its divisors is an integer number (5508960).

Almost surely, 2^21760313 is an apocalyptic number.

It is an amenable number.

21760313 is a deficient number, since it is larger than the sum of its proper divisors (275527).

21760313 is an equidigital number, since it uses as much as digits as its factorization.

21760313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275526.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 21760313 is about 4664.7950651663. The cubic root of 21760313 is about 279.1826204689.

The spelling of 21760313 in words is "twenty-one million, seven hundred sixty thousand, three hundred thirteen".