261646126642320 has 160 divisors (see below), whose sum is σ = 927003999018240. Its totient is φ = 59802948280320.

The previous prime is 261646126642319. The next prime is 261646126642367. The reversal of 261646126642320 is 23246621646162.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 51342340 + ... + 56207900.

It is an arithmetic number, because the mean of its divisors is an integer number (5793774993864).

Almost surely, 2^{261646126642320} is an apocalyptic number.

261646126642320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261646126642320 is an abundant number, since it is smaller than the sum of its proper divisors (665357872375920).

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

261646126642320 is a wasteful number, since it uses less digits than its factorization.

261646126642320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4897593 (or 4897587 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 51.

The spelling of 261646126642320 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred twenty-six million, six hundred forty-two thousand, three hundred twenty".