261684501037646 has 4 divisors (see below), whose sum is σ = 392526751556472. Its totient is φ = 130842250518822.

The previous prime is 261684501037639. The next prime is 261684501037657. The reversal of 261684501037646 is 646730105486162.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65421125259410 + ... + 65421125259413.

It is an arithmetic number, because the mean of its divisors is an integer number (98131687889118).

Almost surely, 2^{261684501037646} is an apocalyptic number.

261684501037646 is a deficient number, since it is larger than the sum of its proper divisors (130842250518826).

261684501037646 is a wasteful number, since it uses less digits than its factorization.

261684501037646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130842250518825.

The product of its (nonzero) digits is 34836480, while the sum is 59.

The spelling of 261684501037646 in words is "two hundred sixty-one trillion, six hundred eighty-four billion, five hundred one million, thirty-seven thousand, six hundred forty-six".