249551689 has 4 divisors (see below), whose sum is σ = 249746580. Its totient is φ = 249356800.

The previous prime is 249551677. The next prime is 249551711. The reversal of 249551689 is 986155942.

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

It can be written as a sum of positive squares in 2 ways, for example, as 236913664 + 12638025 = 15392^2 + 3555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249551689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249551629) 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, 95512 + ... + 98089.

It is an arithmetic number, because the mean of its divisors is an integer number (62436645).

Almost surely, 2^249551689 is an apocalyptic number.

It is an amenable number.

249551689 is a deficient number, since it is larger than the sum of its proper divisors (194891).

249551689 is a wasteful number, since it uses less digits than its factorization.

249551689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194890.

The product of its digits is 777600, while the sum is 49.

The square root of 249551689 is about 15797.2051009031. The cubic root of 249551689 is about 629.5837419925.

The spelling of 249551689 in words is "two hundred forty-nine million, five hundred fifty-one thousand, six hundred eighty-nine".