21877319 has 2 divisors, whose sum is σ = 21877320. Its totient is φ = 21877318.

The previous prime is 21877291. The next prime is 21877321. The reversal of 21877319 is 91377812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21877319 is a prime.

It is a super-2 number, since 2×21877319² = 957234173255522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 21877321, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21877369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10938659 + 10938660.

It is an arithmetic number, because the mean of its divisors is an integer number (10938660).

Almost surely, 2^21877319 is an apocalyptic number.

21877319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21877319 is an equidigital number, since it uses as much as digits as its factorization.

21877319 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 38.

The square root of 21877319 is about 4677.3196384254. The cubic root of 21877319 is about 279.6821179889.

The spelling of 21877319 in words is "twenty-one million, eight hundred seventy-seven thousand, three hundred nineteen".