214551991 has 4 divisors (see below), whose sum is σ = 214581312. Its totient is φ = 214522672.

The previous prime is 214551959. The next prime is 214552043. The reversal of 214551991 is 199155412.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 214551991 - 2⁵ = 214551959 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 214551991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (214551941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6426 + ... + 21688.

It is an arithmetic number, because the mean of its divisors is an integer number (53645328).

Almost surely, 2^214551991 is an apocalyptic number.

214551991 is a deficient number, since it is larger than the sum of its proper divisors (29321).

214551991 is a wasteful number, since it uses less digits than its factorization.

214551991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29320.

The product of its digits is 16200, while the sum is 37.

The square root of 214551991 is about 14647.5933518104. The cubic root of 214551991 is about 598.6562437043.

The spelling of 214551991 in words is "two hundred fourteen million, five hundred fifty-one thousand, nine hundred ninety-one".