251261340349 has 8 divisors (see below), whose sum is σ = 264490395840. Its totient is φ = 238032762336.

The previous prime is 251261340329. The next prime is 251261340361. The reversal of 251261340349 is 943043162152.

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

It is a cyclic number.

It is not a de Polignac number, because 251261340349 - 2⁹ = 251261339837 is a prime.

It is a super-3 number, since 3×251261340349³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251261340329) 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, 1584609 + ... + 1735945.

It is an arithmetic number, because the mean of its divisors is an integer number (33061299480).

Almost surely, 2^251261340349 is an apocalyptic number.

It is an amenable number.

251261340349 is a deficient number, since it is larger than the sum of its proper divisors (13229055491).

251261340349 is a wasteful number, since it uses less digits than its factorization.

251261340349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238739.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 251261340349 in words is "two hundred fifty-one billion, two hundred sixty-one million, three hundred forty thousand, three hundred forty-nine".