261432072665520 has 160 divisors (see below), whose sum is σ = 818503989266880. Its totient is φ = 69024653967360.

The previous prime is 261432072665513. The next prime is 261432072665573. The reversal of 261432072665520 is 25566270234162.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1757505 + ... + 22933664.

It is an arithmetic number, because the mean of its divisors is an integer number (5115649932918).

Almost surely, 2^{261432072665520} is an apocalyptic number.

261432072665520 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 261432072665520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (409251994633440).

261432072665520 is an abundant number, since it is smaller than the sum of its proper divisors (557071916601360).

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

261432072665520 is a wasteful number, since it uses less digits than its factorization.

261432072665520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24691623 (or 24691617 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 51.

The spelling of 261432072665520 in words is "two hundred sixty-one trillion, four hundred thirty-two billion, seventy-two million, six hundred sixty-five thousand, five hundred twenty".