261146550624 has 288 divisors, whose sum is σ = 754042141440. Its totient is φ = 78888775680.

The previous prime is 261146550569. The next prime is 261146550631. The reversal of 261146550624 is 426055641162.

It is a Cunningham number, because it is equal to 511025²-1.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 162504829 + ... + 162506435.

It is an arithmetic number, because the mean of its divisors is an integer number (2618201880).

Almost surely, 2^261146550624 is an apocalyptic number.

261146550624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261146550624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (377021070720).

261146550624 is an abundant number, since it is smaller than the sum of its proper divisors (492895590816).

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

261146550624 is a wasteful number, since it uses less digits than its factorization.

261146550624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1774 (or 1725 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 42.

The spelling of 261146550624 in words is "two hundred sixty-one billion, one hundred forty-six million, five hundred fifty thousand, six hundred twenty-four".