1306661643 has 24 divisors (see below), whose sum is σ = 2160258048. Its totient is φ = 745546032.

The previous prime is 1306661639. The next prime is 1306661693. The reversal of 1306661643 is 3461666031.

It is not a de Polignac number, because 1306661643 - 2² = 1306661639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1306661598 and 1306661607.

It is not an unprimeable number, because it can be changed into a prime (1306661693) 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, 27846 + ... + 58212.

It is an arithmetic number, because the mean of its divisors is an integer number (90010752).

Almost surely, 2^1306661643 is an apocalyptic number.

1306661643 is a deficient number, since it is larger than the sum of its proper divisors (853596405).

1306661643 is a wasteful number, since it uses less digits than its factorization.

1306661643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31063 (or 31060 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 1306661643 is about 36147.7750767596. The cubic root of 1306661643 is about 1093.2539308061.

The spelling of 1306661643 in words is "one billion, three hundred six million, six hundred sixty-one thousand, six hundred forty-three".