261363615342666 has 16 divisors (see below), whose sum is σ = 522736591008000. Its totient is φ = 87119645060448.

The previous prime is 261363615342631. The next prime is 261363615342707. The reversal of 261363615342666 is 666243516363162.

It is a super-2 number, since 2×261363615342666² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 389650426 + ... + 390320613.

It is an arithmetic number, because the mean of its divisors is an integer number (32671036938000).

Almost surely, 2^{261363615342666} is an apocalyptic number.

261363615342666 is an abundant number, since it is smaller than the sum of its proper divisors (261372975665334).

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

261363615342666 is a wasteful number, since it uses less digits than its factorization.

261363615342666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780026893.

The product of its digits is 100776960, while the sum is 60.

The spelling of 261363615342666 in words is "two hundred sixty-one trillion, three hundred sixty-three billion, six hundred fifteen million, three hundred forty-two thousand, six hundred sixty-six".