1321792009 has 4 divisors (see below), whose sum is σ = 1321915716. Its totient is φ = 1321668304.

The previous prime is 1321791983. The next prime is 1321792039. The reversal of 1321792009 is 9002971231.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 631416384 + 690375625 = 25128^2 + 26275^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321792009 - 2⁷ = 1321791881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321792039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44134 + ... + 67759.

It is an arithmetic number, because the mean of its divisors is an integer number (330478929).

Almost surely, 2^1321792009 is an apocalyptic number.

It is an amenable number.

1321792009 is a deficient number, since it is larger than the sum of its proper divisors (123707).

1321792009 is a wasteful number, since it uses less digits than its factorization.

1321792009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123706.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 1321792009 is about 36356.4575969662. The cubic root of 1321792009 is about 1097.4574912059.

The spelling of 1321792009 in words is "one billion, three hundred twenty-one million, seven hundred ninety-two thousand, nine".