261436946280 has 128 divisors (see below), whose sum is σ = 815792947200. Its totient is φ = 66952454400.

The previous prime is 261436946261. The next prime is 261436946333. The reversal of 261436946280 is 82649634162.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 219081 + ... + 755559.

It is an arithmetic number, because the mean of its divisors is an integer number (6373382400).

Almost surely, 2^261436946280 is an apocalyptic number.

261436946280 is a gapful number since it is divisible by the number (20) 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 261436946280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (407896473600).

261436946280 is an abundant number, since it is smaller than the sum of its proper divisors (554356000920).

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

261436946280 is a wasteful number, since it uses less digits than its factorization.

261436946280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536655 (or 536651 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 51.

The spelling of 261436946280 in words is "two hundred sixty-one billion, four hundred thirty-six million, nine hundred forty-six thousand, two hundred eighty".