1261041660 has 36 divisors (see below), whose sum is σ = 3825160248. Its totient is φ = 336277728.

The previous prime is 1261041643. The next prime is 1261041673. The reversal of 1261041660 is 661401621.

1261041660 is a `hidden beast` number, since 1 + 2 + 610 + 41 + 6 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3502714 + ... + 3503073.

Almost surely, 2^1261041660 is an apocalyptic number.

1261041660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261041660 is an abundant number, since it is smaller than the sum of its proper divisors (2564118588).

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

1261041660 is a wasteful number, since it uses less digits than its factorization.

1261041660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7005802 (or 7005797 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 1261041660 is about 35511.1483903295. The cubic root of 1261041660 is about 1080.3798560938.

The spelling of 1261041660 in words is "one billion, two hundred sixty-one million, forty-one thousand, six hundred sixty".