1646979889 has 3 divisors (see below), whose sum is σ = 1647020473. Its totient is φ = 1646939306.

The previous prime is 1646979877. The next prime is 1646979947. The reversal of 1646979889 is 9889796461.

The square root of 1646979889 is 40583.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 1646979889 - 2¹⁵ = 1646947121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1646979289) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 20292 + ... + 60874.

Almost surely, 2^1646979889 is an apocalyptic number.

1646979889 is the 40583-rd square number.

1646979889 is the 20292-nd centered octagonal number.

It is an amenable number.

1646979889 is a deficient number, since it is larger than the sum of its proper divisors (40584).

1646979889 is an frugal number, since it uses more digits than its factorization.

1646979889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81166 (or 40583 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 67.

The cubic root of 1646979889 is about 1180.9443481779.

The spelling of 1646979889 in words is "one billion, six hundred forty-six million, nine hundred seventy-nine thousand, eight hundred eighty-nine".