261554755720260 has 384 divisors, whose sum is σ = 766140786851328. Its totient is φ = 66613487616000.

The previous prime is 261554755720253. The next prime is 261554755720277. The reversal of 261554755720260 is 62027557455162.

It is a self number, because there is not a number n which added to its sum of digits gives 261554755720260.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 42439515939 + ... + 42439522101.

It is an arithmetic number, because the mean of its divisors is an integer number (1995158299092).

Almost surely, 2^{261554755720260} is an apocalyptic number.

261554755720260 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 261554755720260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383070393425664).

261554755720260 is an abundant number, since it is smaller than the sum of its proper divisors (504586031131068).

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

261554755720260 is a wasteful number, since it uses less digits than its factorization.

261554755720260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7575 (or 7573 counting only the distinct ones).

The product of its (nonzero) digits is 35280000, while the sum is 57.

The spelling of 261554755720260 in words is "two hundred sixty-one trillion, five hundred fifty-four billion, seven hundred fifty-five million, seven hundred twenty thousand, two hundred sixty".