261767332440 has 192 divisors, whose sum is σ = 861775200000. Its totient is φ = 68904317952.

The previous prime is 261767332433. The next prime is 261767332457. The reversal of 261767332440 is 44233767162.

261767332440 is a `hidden beast` number, since 2 + 6 + 176 + 7 + 3 + 32 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10543161 + ... + 10567959.

It is an arithmetic number, because the mean of its divisors is an integer number (4488412500).

Almost surely, 2^261767332440 is an apocalyptic number.

261767332440 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 261767332440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (430887600000).

261767332440 is an abundant number, since it is smaller than the sum of its proper divisors (600007867560).

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

261767332440 is a wasteful number, since it uses less digits than its factorization.

261767332440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25194 (or 25187 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 45.

The spelling of 261767332440 in words is "two hundred sixty-one billion, seven hundred sixty-seven million, three hundred thirty-two thousand, four hundred forty".