249391691 has 4 divisors (see below), whose sum is σ = 260234832. Its totient is φ = 238548552.

The previous prime is 249391679. The next prime is 249391693. The reversal of 249391691 is 196193942.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 249391691 - 2¹⁰ = 249390667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249391693) 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, 5421536 + ... + 5421581.

It is an arithmetic number, because the mean of its divisors is an integer number (65058708).

Almost surely, 2^249391691 is an apocalyptic number.

249391691 is a deficient number, since it is larger than the sum of its proper divisors (10843141).

249391691 is a wasteful number, since it uses less digits than its factorization.

249391691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10843140.

The product of its digits is 104976, while the sum is 44.

The square root of 249391691 is about 15792.1401652848. The cubic root of 249391691 is about 629.4491624250.

The spelling of 249391691 in words is "two hundred forty-nine million, three hundred ninety-one thousand, six hundred ninety-one".