21313147 has 4 divisors (see below), whose sum is σ = 21889216. Its totient is φ = 20737080.

The previous prime is 21313133. The next prime is 21313181. The reversal of 21313147 is 74131312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21313147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21313247) 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, 287979 + ... + 288052.

It is an arithmetic number, because the mean of its divisors is an integer number (5472304).

Almost surely, 2^21313147 is an apocalyptic number.

21313147 is a deficient number, since it is larger than the sum of its proper divisors (576069).

21313147 is an equidigital number, since it uses as much as digits as its factorization.

21313147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576068.

The product of its digits is 504, while the sum is 22.

The square root of 21313147 is about 4616.6164016518. The cubic root of 21313147 is about 277.2570044980.

Adding to 21313147 its reverse (74131312), we get a palindrome (95444459).

The spelling of 21313147 in words is "twenty-one million, three hundred thirteen thousand, one hundred forty-seven".