249640121 has 8 divisors (see below), whose sum is σ = 268659144. Its totient is φ = 231102720.

The previous prime is 249640093. The next prime is 249640129. The reversal of 249640121 is 121046942.

It can be written as a sum of positive squares in 4 ways, for example, as 8179600 + 241460521 = 2860^2 + 15539^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249640121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249640129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119330 + ... + 121403.

It is an arithmetic number, because the mean of its divisors is an integer number (33582393).

Almost surely, 2^249640121 is an apocalyptic number.

It is an amenable number.

249640121 is a deficient number, since it is larger than the sum of its proper divisors (19019023).

249640121 is a wasteful number, since it uses less digits than its factorization.

249640121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240811.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 249640121 is about 15800.0038291135. The cubic root of 249640121 is about 629.6581003676.

The spelling of 249640121 in words is "two hundred forty-nine million, six hundred forty thousand, one hundred twenty-one".