261286467280 has 40 divisors (see below), whose sum is σ = 607708441224. Its totient is φ = 104477184000.

The previous prime is 261286467271. The next prime is 261286467283. The reversal of 261286467280 is 82764682162.

It can be written as a sum of positive squares in 4 ways, for example, as 14050783296 + 247235683984 = 118536^2 + 497228^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261286467283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 358941 + ... + 807100.

Almost surely, 2^261286467280 is an apocalyptic number.

261286467280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261286467280 is an abundant number, since it is smaller than the sum of its proper divisors (346421973944).

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

261286467280 is a wasteful number, since it uses less digits than its factorization.

261286467280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1168855 (or 1168849 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 52.

The spelling of 261286467280 in words is "two hundred sixty-one billion, two hundred eighty-six million, four hundred sixty-seven thousand, two hundred eighty".