249716639 has 4 divisors (see below), whose sum is σ = 262859640. Its totient is φ = 236573640.

The previous prime is 249716633. The next prime is 249716641. The reversal of 249716639 is 936617942.

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 249716639 - 2¹² = 249712543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 249716593 and 249716602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249716633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6571472 + ... + 6571509.

It is an arithmetic number, because the mean of its divisors is an integer number (65714910).

Almost surely, 2^249716639 is an apocalyptic number.

249716639 is a deficient number, since it is larger than the sum of its proper divisors (13143001).

249716639 is a wasteful number, since it uses less digits than its factorization.

249716639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13143000.

The product of its digits is 489888, while the sum is 47.

The square root of 249716639 is about 15802.4250986992. The cubic root of 249716639 is about 629.7224266420.

The spelling of 249716639 in words is "two hundred forty-nine million, seven hundred sixteen thousand, six hundred thirty-nine".