261777754464 has 24 divisors (see below), whose sum is σ = 687166605720. Its totient is φ = 87259251456.

The previous prime is 261777754457. The next prime is 261777754481. The reversal of 261777754464 is 464457777162.

261777754464 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (24).

It is a junction number, because it is equal to n+sod(n) for n = 261777754398 and 261777754407.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1363425709 + ... + 1363425900.

It is an arithmetic number, because the mean of its divisors is an integer number (28631941905).

Almost surely, 2^261777754464 is an apocalyptic number.

261777754464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261777754464 is an abundant number, since it is smaller than the sum of its proper divisors (425388851256).

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

261777754464 is a wasteful number, since it uses less digits than its factorization.

261777754464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2726851622 (or 2726851614 counting only the distinct ones).

The product of its digits is 55319040, while the sum is 60.

The spelling of 261777754464 in words is "two hundred sixty-one billion, seven hundred seventy-seven million, seven hundred fifty-four thousand, four hundred sixty-four".