261931415316480 has 3072 divisors, whose sum is σ = 1211915619532800. Its totient is φ = 52171112448000.

The previous prime is 261931415316463. The next prime is 261931415316491. The reversal of 261931415316480 is 84613514139162.

261931415316480 is a `hidden beast` number, since 2 + 6 + 1 + 9 + 3 + 1 + 4 + 153 + 1 + 6 + 480 = 666.

It is a tau number, because it is divible by the number of its divisors (3072).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 31977949185 + ... + 31977957375.

It is an arithmetic number, because the mean of its divisors is an integer number (394503782400).

Almost surely, 2^{261931415316480} is an apocalyptic number.

261931415316480 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 261931415316480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (605957809766400).

261931415316480 is an abundant number, since it is smaller than the sum of its proper divisors (949984204216320).

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

261931415316480 is a wasteful number, since it uses less digits than its factorization.

261931415316480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8319 (or 8293 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The spelling of 261931415316480 in words is "two hundred sixty-one trillion, nine hundred thirty-one billion, four hundred fifteen million, three hundred sixteen thousand, four hundred eighty".