251662091 has 2 divisors, whose sum is σ = 251662092. Its totient is φ = 251662090.

The previous prime is 251662079. The next prime is 251662109. The reversal of 251662091 is 190266152.

It is a happy number.

Together with next prime (251662109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251662091 - 2¹⁸ = 251399947 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (251662001) 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, 125831045 + 125831046.

It is an arithmetic number, because the mean of its divisors is an integer number (125831046).

Almost surely, 2^251662091 is an apocalyptic number.

251662091 is a deficient number, since it is larger than the sum of its proper divisors (1).

251662091 is an equidigital number, since it uses as much as digits as its factorization.

251662091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 251662091 is about 15863.8611630334. The cubic root of 251662091 is about 631.3535114246.

The spelling of 251662091 in words is "two hundred fifty-one million, six hundred sixty-two thousand, ninety-one".