1261013040 has 360 divisors, whose sum is σ = 5089638528. Its totient is φ = 278691840.

The previous prime is 1261013027. The next prime is 1261013081. The reversal of 1261013040 is 403101621.

It is a happy number.

1261013040 is a `hidden beast` number, since 1 + 2 + 610 + 13 + 0 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 71 ways as a sum of consecutive naturals, for example, 1093104 + ... + 1094256.

Almost surely, 2^1261013040 is an apocalyptic number.

1261013040 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 1261013040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2544819264).

1261013040 is an abundant number, since it is smaller than the sum of its proper divisors (3828625488).

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

1261013040 is a wasteful number, since it uses less digits than its factorization.

1261013040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217 (or 1201 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1261013040 is about 35510.7454160005. The cubic root of 1261013040 is about 1080.3716827700.

Adding to 1261013040 its reverse (403101621), we get a palindrome (1664114661).

The spelling of 1261013040 in words is "one billion, two hundred sixty-one million, thirteen thousand, forty".