21877313 has 4 divisors (see below), whose sum is σ = 22410948. Its totient is φ = 21343680.

The previous prime is 21877291. The next prime is 21877319. The reversal of 21877313 is 31377812.

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

It can be written as a sum of positive squares in 2 ways, for example, as 652864 + 21224449 = 808^2 + 4607^2 .

It is a cyclic number.

It is not a de Polignac number, because 21877313 - 2¹² = 21873217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21877313.

It is not an unprimeable number, because it can be changed into a prime (21877319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266756 + ... + 266837.

It is an arithmetic number, because the mean of its divisors is an integer number (5602737).

Almost surely, 2^21877313 is an apocalyptic number.

It is an amenable number.

21877313 is a deficient number, since it is larger than the sum of its proper divisors (533635).

21877313 is an equidigital number, since it uses as much as digits as its factorization.

21877313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533634.

The product of its digits is 7056, while the sum is 32.

The square root of 21877313 is about 4677.3189970324. The cubic root of 21877313 is about 279.6820924207.

The spelling of 21877313 in words is "twenty-one million, eight hundred seventy-seven thousand, three hundred thirteen".