1309689538 has 16 divisors (see below), whose sum is σ = 1986387480. Its totient is φ = 647571456.

The previous prime is 1309689487. The next prime is 1309689541. The reversal of 1309689538 is 8359869031.

It can be written as a sum of positive squares in 4 ways, for example, as 1065173769 + 244515769 = 32637^2 + 15637^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 369358 + ... + 372886.

Almost surely, 2^1309689538 is an apocalyptic number.

1309689538 is a deficient number, since it is larger than the sum of its proper divisors (676697942).

1309689538 is a wasteful number, since it uses less digits than its factorization.

1309689538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5541.

The product of its (nonzero) digits is 1399680, while the sum is 52.

The square root of 1309689538 is about 36189.6330183106. The cubic root of 1309689538 is about 1094.0977362112.

The spelling of 1309689538 in words is "one billion, three hundred nine million, six hundred eighty-nine thousand, five hundred thirty-eight".