261490612240 has 480 divisors, whose sum is σ = 786777643008. Its totient is φ = 79924838400.

The previous prime is 261490612193. The next prime is 261490612249. The reversal of 261490612240 is 42216094162.

It is a self number, because there is not a number n which added to its sum of digits gives 261490612240.

It is not an unprimeable number, because it can be changed into a prime (261490612249) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 66315709 + ... + 66319651.

Almost surely, 2^261490612240 is an apocalyptic number.

261490612240 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 261490612240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (393388821504).

261490612240 is an abundant number, since it is smaller than the sum of its proper divisors (525287030768).

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

261490612240 is a wasteful number, since it uses less digits than its factorization.

261490612240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4039 (or 4022 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The spelling of 261490612240 in words is "two hundred sixty-one billion, four hundred ninety million, six hundred twelve thousand, two hundred forty".