261261016064355 has 64 divisors (see below), whose sum is σ = 420491357475840. Its totient is φ = 138517266640896.

The previous prime is 261261016064329. The next prime is 261261016064371. The reversal of 261261016064355 is 553460610162162.

It is a happy number.

261261016064355 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261261016064355 - 2¹² = 261261016060259 is a prime.

It is a super-2 number, since 2×261261016064355² (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 63 ways as a sum of consecutive naturals, for example, 6517330122 + ... + 6517370208.

It is an arithmetic number, because the mean of its divisors is an integer number (6570177460560).

Almost surely, 2^{261261016064355} is an apocalyptic number.

261261016064355 is a deficient number, since it is larger than the sum of its proper divisors (159230341411485).

261261016064355 is a wasteful number, since it uses less digits than its factorization.

261261016064355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44140.

The product of its (nonzero) digits is 1555200, while the sum is 48.

The spelling of 261261016064355 in words is "two hundred sixty-one trillion, two hundred sixty-one billion, sixteen million, sixty-four thousand, three hundred fifty-five".