261501411640 has 64 divisors (see below), whose sum is σ = 690606072000. Its totient is φ = 87234444288.

The previous prime is 261501411539. The next prime is 261501411641. The reversal of 261501411640 is 46114105162.

261501411640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261501411641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12610365 + ... + 12631084.

It is an arithmetic number, because the mean of its divisors is an integer number (10790719875).

Almost surely, 2^261501411640 is an apocalyptic number.

261501411640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261501411640 is an abundant number, since it is smaller than the sum of its proper divisors (429104660360).

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

261501411640 is a wasteful number, since it uses less digits than its factorization.

261501411640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25241504 (or 25241500 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The spelling of 261501411640 in words is "two hundred sixty-one billion, five hundred one million, four hundred eleven thousand, six hundred forty".