212891137 has 4 divisors (see below), whose sum is σ = 212924160. Its totient is φ = 212858116.

The previous prime is 212891101. The next prime is 212891179. The reversal of 212891137 is 731198212.

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 a de Polignac number, because none of the positive numbers 2^k-212891137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212892137) 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, 3337 + ... + 20902.

It is an arithmetic number, because the mean of its divisors is an integer number (53231040).

Almost surely, 2^212891137 is an apocalyptic number.

It is an amenable number.

212891137 is a deficient number, since it is larger than the sum of its proper divisors (33023).

212891137 is an equidigital number, since it uses as much as digits as its factorization.

212891137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33022.

The product of its digits is 6048, while the sum is 34.

The square root of 212891137 is about 14590.7894577367. The cubic root of 212891137 is about 597.1075013080.

The spelling of 212891137 in words is "two hundred twelve million, eight hundred ninety-one thousand, one hundred thirty-seven".