261190805040 has 960 divisors, whose sum is σ = 1050436767744. Its totient is φ = 59781888000.

The previous prime is 261190804993. The next prime is 261190805129. The reversal of 261190805040 is 40508091162.

261190805040 is a `hidden beast` number, since 2 + 61 + 1 + 90 + 8 + 0 + 504 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 261190804986 and 261190805004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 6370507420 + ... + 6370507460.

Almost surely, 2^261190805040 is an apocalyptic number.

261190805040 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 261190805040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (525218383872).

261190805040 is an abundant number, since it is smaller than the sum of its proper divisors (789245962704).

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

261190805040 is an equidigital number, since it uses as much as digits as its factorization.

261190805040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 261190805040 in words is "two hundred sixty-one billion, one hundred ninety million, eight hundred five thousand, forty".