1309209012 has 36 divisors (see below), whose sum is σ = 3321716580. Its totient is φ = 434777472.

The previous prime is 1309208983. The next prime is 1309209037. The reversal of 1309209012 is 2109029031.

It can be written as a sum of positive squares in 2 ways, for example, as 509224356 + 799984656 = 22566^2 + 28284^2 .

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

It is a super-2 number, since 2×1309209012² = 3428056474204032288, which contains 22 as substring.

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, 57913 + ... + 77280.

It is an arithmetic number, because the mean of its divisors is an integer number (92269905).

Almost surely, 2^1309209012 is an apocalyptic number.

1309209012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1309209012 is an abundant number, since it is smaller than the sum of its proper divisors (2012507568).

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

1309209012 is a wasteful number, since it uses less digits than its factorization.

1309209012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135472 (or 135467 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 1309209012 is about 36182.9934085062. The cubic root of 1309209012 is about 1093.9639114369.

The spelling of 1309209012 in words is "one billion, three hundred nine million, two hundred nine thousand, twelve".