261130401840 has 640 divisors, whose sum is σ = 1072274227200. Its totient is φ = 50925957120.

The previous prime is 261130401797. The next prime is 261130401853. The reversal of 261130401840 is 48104031162.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 261130401798 and 261130401807.

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, 38268669 + ... + 38275491.

It is an arithmetic number, because the mean of its divisors is an integer number (1675428480).

Almost surely, 2^261130401840 is an apocalyptic number.

261130401840 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 261130401840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (536137113600).

261130401840 is an abundant number, since it is smaller than the sum of its proper divisors (811143825360).

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

261130401840 is a wasteful number, since it uses less digits than its factorization.

261130401840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6985 (or 6979 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The spelling of 261130401840 in words is "two hundred sixty-one billion, one hundred thirty million, four hundred one thousand, eight hundred forty".