261646776147520 has 112 divisors (see below), whose sum is σ = 626798760916608. Its totient is φ = 104028433367040.

The previous prime is 261646776147469. The next prime is 261646776147521. The reversal of 261646776147520 is 25741677646162.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is not an unprimeable number, because it can be changed into a prime (261646776147521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1996613200 + ... + 1996744240.

It is an arithmetic number, because the mean of its divisors is an integer number (5596417508184).

Almost surely, 2^{261646776147520} is an apocalyptic number.

261646776147520 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 261646776147520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313399380458304).

261646776147520 is an abundant number, since it is smaller than the sum of its proper divisors (365151984769088).

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

261646776147520 is a wasteful number, since it uses less digits than its factorization.

261646776147520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168588 (or 168578 counting only the distinct ones).

The product of its (nonzero) digits is 142248960, while the sum is 64.

The spelling of 261646776147520 in words is "two hundred sixty-one trillion, six hundred forty-six billion, seven hundred seventy-six million, one hundred forty-seven thousand, five hundred twenty".