261566782096 has 15 divisors (see below), whose sum is σ = 506789603971. Its totient is φ = 130782368176.

The previous prime is 261566782069. The next prime is 261566782097. The reversal of 261566782096 is 690287665162.

The square root of 261566782096 is 511436.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261566782096.

It is not an unprimeable number, because it can be changed into a prime (261566782097) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1981815 + ... + 2109673.

Almost surely, 2^261566782096 is an apocalyptic number.

261566782096 is the 511436-th square number.

It is an amenable number.

261566782096 is a deficient number, since it is larger than the sum of its proper divisors (245222821875).

261566782096 is an frugal number, since it uses more digits than its factorization.

261566782096 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255726 (or 127861 counting only the distinct ones).

The product of its (nonzero) digits is 13063680, while the sum is 58.

The spelling of 261566782096 in words is "two hundred sixty-one billion, five hundred sixty-six million, seven hundred eighty-two thousand, ninety-six".