213915881 has 2 divisors, whose sum is σ = 213915882. Its totient is φ = 213915880.

The previous prime is 213915869. The next prime is 213915883. The reversal of 213915881 is 188519312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202920025 + 10995856 = 14245^2 + 3316^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213915881 is a prime.

It is a super-2 number, since 2×213915881² = 91520008288012322, which contains 22 as substring.

Together with 213915883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (213915883) 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 as a sum of consecutive naturals, namely, 106957940 + 106957941.

It is an arithmetic number, because the mean of its divisors is an integer number (106957941).

Almost surely, 2^213915881 is an apocalyptic number.

It is an amenable number.

213915881 is a deficient number, since it is larger than the sum of its proper divisors (1).

213915881 is an equidigital number, since it uses as much as digits as its factorization.

213915881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 38.

The square root of 213915881 is about 14625.8634275040. The cubic root of 213915881 is about 598.0640202075.

It can be divided in two parts, 21391 and 5881, that added together give a palindrome (27272).

The spelling of 213915881 in words is "two hundred thirteen million, nine hundred fifteen thousand, eight hundred eighty-one".