256611749 has 8 divisors (see below), whose sum is σ = 265645920. Its totient is φ = 247590000.

The previous prime is 256611721. The next prime is 256611757. The reversal of 256611749 is 947116652.

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 256611749 - 2²⁴ = 239834533 is a prime.

It is a super-3 number, since 3×256611749³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256611779) 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, 63314 + ... + 67244.

It is an arithmetic number, because the mean of its divisors is an integer number (33205740).

Almost surely, 2^256611749 is an apocalyptic number.

256611749 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

256611749 is a deficient number, since it is larger than the sum of its proper divisors (9034171).

256611749 is a wasteful number, since it uses less digits than its factorization.

256611749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6211.

The product of its digits is 90720, while the sum is 41.

The square root of 256611749 is about 16019.1057490735. The cubic root of 256611749 is about 635.4657950116.

The spelling of 256611749 in words is "two hundred fifty-six million, six hundred eleven thousand, seven hundred forty-nine".