249808651 has 2 divisors, whose sum is σ = 249808652. Its totient is φ = 249808650.

The previous prime is 249808649. The next prime is 249808667. The reversal of 249808651 is 156808942.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 249808651 - 2¹ = 249808649 is a prime.

It is a super-2 number, since 2×249808651² = 124808724228879602, which contains 22 as substring.

Together with 249808649, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 249808598 and 249808607.

It is not a weakly prime, because it can be changed into another prime (249808631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124904325 + 124904326.

It is an arithmetic number, because the mean of its divisors is an integer number (124904326).

Almost surely, 2^249808651 is an apocalyptic number.

249808651 is a deficient number, since it is larger than the sum of its proper divisors (1).

249808651 is an equidigital number, since it uses as much as digits as its factorization.

249808651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 249808651 is about 15805.3361558684. The cubic root of 249808651 is about 629.7997608357.

The spelling of 249808651 in words is "two hundred forty-nine million, eight hundred eight thousand, six hundred fifty-one".