261646246526140 has 72 divisors (see below), whose sum is σ = 639423493828560. Its totient is φ = 89670920790528.

The previous prime is 261646246526129. The next prime is 261646246526141. The reversal of 261646246526140 is 41625642646162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261646246526141) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 51693805 + ... + 56529124.

It is an arithmetic number, because the mean of its divisors is an integer number (8880881858730).

Almost surely, 2^{261646246526140} is an apocalyptic number.

261646246526140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261646246526140 is an abundant number, since it is smaller than the sum of its proper divisors (377777247302420).

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

261646246526140 is a wasteful number, since it uses less digits than its factorization.

261646246526140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108225419 (or 108225410 counting only the distinct ones).

The product of its (nonzero) digits is 19906560, while the sum is 55.

The spelling of 261646246526140 in words is "two hundred sixty-one trillion, six hundred forty-six billion, two hundred forty-six million, five hundred twenty-six thousand, one hundred forty".