1261068660 has 72 divisors (see below), whose sum is σ = 3828693960. Its totient is φ = 335981568.

The previous prime is 1261068647. The next prime is 1261068667. The reversal of 1261068660 is 668601621.

It can be written as a sum of positive squares in 4 ways, for example, as 406909584 + 854159076 = 20172^2 + 29226^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261068667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 255496 + ... + 260384.

It is an arithmetic number, because the mean of its divisors is an integer number (53176305).

Almost surely, 2^1261068660 is an apocalyptic number.

1261068660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261068660 is an abundant number, since it is smaller than the sum of its proper divisors (2567625300).

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

1261068660 is a wasteful number, since it uses less digits than its factorization.

1261068660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6337 (or 6332 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 1261068660 is about 35511.5285505989. The cubic root of 1261068660 is about 1080.3875666633.

The spelling of 1261068660 in words is "one billion, two hundred sixty-one million, sixty-eight thousand, six hundred sixty".