261563335322464 has 24 divisors (see below), whose sum is σ = 588517504476048. Its totient is φ = 112098572280960.

The previous prime is 261563335322431. The next prime is 261563335322483. The reversal of 261563335322464 is 464223533365162.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 583846730407 + ... + 583846730854.

It is an arithmetic number, because the mean of its divisors is an integer number (24521562686502).

Almost surely, 2^{261563335322464} is an apocalyptic number.

It is an amenable number.

261563335322464 is an abundant number, since it is smaller than the sum of its proper divisors (326954169153584).

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

261563335322464 is a wasteful number, since it uses less digits than its factorization.

261563335322464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1167693461278 (or 1167693461270 counting only the distinct ones).

The product of its digits is 55987200, while the sum is 55.

The spelling of 261563335322464 in words is "two hundred sixty-one trillion, five hundred sixty-three billion, three hundred thirty-five million, three hundred twenty-two thousand, four hundred sixty-four".