16389646634 has 4 divisors (see below), whose sum is σ = 24584469954. Its totient is φ = 8194823316.

The previous prime is 16389646631. The next prime is 16389646661. The reversal of 16389646634 is 43664698361.

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

It can be written as a sum of positive squares in only one way, i.e., 15965080609 + 424566025 = 126353^2 + 20605^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16389646634.

It is not an unprimeable number, because it can be changed into a prime (16389646631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4097411657 + ... + 4097411660.

Almost surely, 2^16389646634 is an apocalyptic number.

16389646634 is a deficient number, since it is larger than the sum of its proper divisors (8194823320).

16389646634 is an equidigital number, since it uses as much as digits as its factorization.

16389646634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8194823319.

The product of its digits is 13436928, while the sum is 56.

The spelling of 16389646634 in words is "sixteen billion, three hundred eighty-nine million, six hundred forty-six thousand, six hundred thirty-four".