261779460 has 96 divisors (see below), whose sum is σ = 756362880. Its totient is φ = 67617792.

The previous prime is 261779437. The next prime is 261779503. The reversal of 261779460 is 64977162.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 257914 + ... + 258926.

It is an arithmetic number, because the mean of its divisors is an integer number (7878780).

Almost surely, 2^261779460 is an apocalyptic number.

261779460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261779460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (378181440).

261779460 is an abundant number, since it is smaller than the sum of its proper divisors (494583420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261779460 is a wasteful number, since it uses less digits than its factorization.

261779460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157 (or 1155 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 261779460 is about 16179.6001186680. The cubic root of 261779460 is about 639.7031989679.

The spelling of 261779460 in words is "two hundred sixty-one million, seven hundred seventy-nine thousand, four hundred sixty".