1261643112 has 24 divisors (see below), whose sum is σ = 3416950290. Its totient is φ = 420547680.

The previous prime is 1261643093. The next prime is 1261643113. The reversal of 1261643112 is 2113461621.

It is a happy number.

1261643112 is a `hidden beast` number, since 1 + 2 + 6 + 1 + 643 + 1 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 635342436 + 626300676 = 25206^2 + 25026^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1261643113) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8761339 + ... + 8761482.

Almost surely, 2^1261643112 is an apocalyptic number.

1261643112 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1261643112 is an abundant number, since it is smaller than the sum of its proper divisors (2155307178).

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

1261643112 is a wasteful number, since it uses less digits than its factorization.

1261643112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17522833 (or 17522826 counting only the distinct ones).

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

The square root of 1261643112 is about 35519.6158763014. The cubic root of 1261643112 is about 1080.5515906650.

The spelling of 1261643112 in words is "one billion, two hundred sixty-one million, six hundred forty-three thousand, one hundred twelve".