261432140172544 has 144 divisors (see below), whose sum is σ = 580633480453824. Its totient is φ = 116468258816000.

The previous prime is 261432140172529. The next prime is 261432140172551. The reversal of 261432140172544 is 445271041234162.

It is a junction number, because it is equal to n+sod(n) for n = 261432140172494 and 261432140172503.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141314319 + ... + 143152369.

It is an arithmetic number, because the mean of its divisors is an integer number (4032176947596).

Almost surely, 2^{261432140172544} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261432140172544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290316740226912).

261432140172544 is an abundant number, since it is smaller than the sum of its proper divisors (319201340281280).

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

261432140172544 is a wasteful number, since it uses less digits than its factorization.

261432140172544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1839084 (or 1839070 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 46.

The spelling of 261432140172544 in words is "two hundred sixty-one trillion, four hundred thirty-two billion, one hundred forty million, one hundred seventy-two thousand, five hundred forty-four".