2391994043209 has 4 divisors (see below), whose sum is σ = 2393183500240. Its totient is φ = 2390804586180.

The previous prime is 2391994043071. The next prime is 2391994043261. The reversal of 2391994043209 is 9023404991932.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2391994043209 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2391994043209.

It is not an unprimeable number, because it can be changed into a prime (2391991043209) 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, 594725499 + ... + 594729520.

It is an arithmetic number, because the mean of its divisors is an integer number (598295875060).

Almost surely, 2^{2391994043209} is an apocalyptic number.

It is an amenable number.

2391994043209 is a deficient number, since it is larger than the sum of its proper divisors (1189457031).

2391994043209 is a wasteful number, since it uses less digits than its factorization.

2391994043209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189457030.

The product of its (nonzero) digits is 3779136, while the sum is 55.

The spelling of 2391994043209 in words is "two trillion, three hundred ninety-one billion, nine hundred ninety-four million, forty-three thousand, two hundred nine".