261531034692480 has 5120 divisors, whose sum is σ = 1198132450099200. Its totient is φ = 53074074009600.

The previous prime is 261531034692463. The next prime is 261531034692503. The reversal of 261531034692480 is 84296430135162.

It is a happy number.

261531034692480 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 31 + 0 + 3 + 46 + 92 + 480 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 639 ways as a sum of consecutive naturals, for example, 567312439450 + ... + 567312439910.

It is an arithmetic number, because the mean of its divisors is an integer number (234010244160).

Almost surely, 2^{261531034692480} is an apocalyptic number.

261531034692480 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 261531034692480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (599066225049600).

261531034692480 is an abundant number, since it is smaller than the sum of its proper divisors (936601415406720).

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

261531034692480 is a wasteful number, since it uses less digits than its factorization.

261531034692480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 622 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 261531034692480 in words is "two hundred sixty-one trillion, five hundred thirty-one billion, thirty-four million, six hundred ninety-two thousand, four hundred eighty".