249878779 has 2 divisors, whose sum is σ = 249878780. Its totient is φ = 249878778.

The previous prime is 249878777. The next prime is 249878791. The reversal of 249878779 is 977878942.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 249878779 - 2¹ = 249878777 is a prime.

Together with 249878777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (249878773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124939389 + 124939390.

It is an arithmetic number, because the mean of its divisors is an integer number (124939390).

Almost surely, 2^249878779 is an apocalyptic number.

249878779 is a deficient number, since it is larger than the sum of its proper divisors (1).

249878779 is an equidigital number, since it uses as much as digits as its factorization.

249878779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14224896, while the sum is 61.

The square root of 249878779 is about 15807.5544914449. The cubic root of 249878779 is about 629.8586892264.

The spelling of 249878779 in words is "two hundred forty-nine million, eight hundred seventy-eight thousand, seven hundred seventy-nine".