6197721389 has 4 divisors (see below), whose sum is σ = 6282621756. Its totient is φ = 6112821024.

The previous prime is 6197721379. The next prime is 6197721401. The reversal of 6197721389 is 9831277916.

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 4478955625 + 1718765764 = 66925^2 + 41458^2 .

It is a cyclic number.

It is not a de Polignac number, because 6197721389 - 2¹⁶ = 6197655853 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 6197721389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6197721319) 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, 42450074 + ... + 42450219.

It is an arithmetic number, because the mean of its divisors is an integer number (1570655439).

Almost surely, 2^6197721389 is an apocalyptic number.

It is an amenable number.

6197721389 is a deficient number, since it is larger than the sum of its proper divisors (84900367).

6197721389 is an equidigital number, since it uses as much as digits as its factorization.

6197721389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84900366.

The product of its digits is 1143072, while the sum is 53.

The square root of 6197721389 is about 78725.6082161326. The cubic root of 6197721389 is about 1836.8654678824.

The spelling of 6197721389 in words is "six billion, one hundred ninety-seven million, seven hundred twenty-one thousand, three hundred eighty-nine".