1261146240 has 256 divisors, whose sum is σ = 4545936000. Its totient is φ = 330338304.

The previous prime is 1261146217. The next prime is 1261146259. The reversal of 1261146240 is 426411621.

1261146240 is a `hidden beast` number, since 1 + 2 + 611 + 4 + 6 + 2 + 40 = 666.

It is a super-2 number, since 2×1261146240² = 3180979677332275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1018902 + ... + 1020138.

Almost surely, 2^1261146240 is an apocalyptic number.

1261146240 is a gapful number since it is divisible by the number (10) 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 1261146240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2272968000).

1261146240 is an abundant number, since it is smaller than the sum of its proper divisors (3284789760).

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

1261146240 is a wasteful number, since it uses less digits than its factorization.

1261146240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1324 (or 1306 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 1261146240 is about 35512.6208551270. The cubic root of 1261146240 is about 1080.4097210871.

Adding to 1261146240 its reverse (426411621), we get a palindrome (1687557861).

The spelling of 1261146240 in words is "one billion, two hundred sixty-one million, one hundred forty-six thousand, two hundred forty".