261237832780 has 48 divisors (see below), whose sum is σ = 611442125280. Its totient is φ = 93172128768.

The previous prime is 261237832771. The next prime is 261237832781. The reversal of 261237832780 is 87238732162.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (261237832781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20213187 + ... + 20226106.

It is an arithmetic number, because the mean of its divisors is an integer number (12738377610).

Almost surely, 2^261237832780 is an apocalyptic number.

261237832780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261237832780 is an abundant number, since it is smaller than the sum of its proper divisors (350204292500).

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

261237832780 is a wasteful number, since it uses less digits than its factorization.

261237832780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40439338 (or 40439336 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 49.

The spelling of 261237832780 in words is "two hundred sixty-one billion, two hundred thirty-seven million, eight hundred thirty-two thousand, seven hundred eighty".