261798154240 has 208 divisors, whose sum is σ = 742757258880. Its totient is φ = 86662840320.

The previous prime is 261798154231. The next prime is 261798154279. The reversal of 261798154240 is 42451897162.

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, 4125955 + ... + 4188925.

It is an arithmetic number, because the mean of its divisors is an integer number (3570948360).

Almost surely, 2^261798154240 is an apocalyptic number.

261798154240 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 261798154240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (371378629440).

261798154240 is an abundant number, since it is smaller than the sum of its proper divisors (480959104640).

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

261798154240 is an equidigital number, since it uses as much as digits as its factorization.

261798154240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63036 (or 63014 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 261798154240 in words is "two hundred sixty-one billion, seven hundred ninety-eight million, one hundred fifty-four thousand, two hundred forty".