261776760 has 128 divisors (see below), whose sum is σ = 903052800. Its totient is φ = 59466240.

The previous prime is 261776747. The next prime is 261776773. The reversal of 261776760 is 67677162.

It is an interprime number because it is at equal distance from previous prime (261776747) and next prime (261776773).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

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, 149490 + ... + 151230.

It is an arithmetic number, because the mean of its divisors is an integer number (7055100).

Almost surely, 2^261776760 is an apocalyptic number.

261776760 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 261776760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (451526400).

261776760 is an abundant number, since it is smaller than the sum of its proper divisors (641276040).

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

261776760 is a wasteful number, since it uses less digits than its factorization.

261776760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1941 (or 1937 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 42.

The square root of 261776760 is about 16179.5166800495. The cubic root of 261776760 is about 639.7009996553.

The spelling of 261776760 in words is "two hundred sixty-one million, seven hundred seventy-six thousand, seven hundred sixty".