16401789685 has 4 divisors (see below), whose sum is σ = 19682147628. Its totient is φ = 13121431744.

The previous prime is 16401789673. The next prime is 16401789757. The reversal of 16401789685 is 58698710461.

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 9486370404 + 6915419281 = 97398^2 + 83159^2 .

It is a cyclic number.

It is not a de Polignac number, because 16401789685 - 2⁷ = 16401789557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1640178964 + ... + 1640178973.

It is an arithmetic number, because the mean of its divisors is an integer number (4920536907).

Almost surely, 2^16401789685 is an apocalyptic number.

It is an amenable number.

16401789685 is a deficient number, since it is larger than the sum of its proper divisors (3280357943).

16401789685 is an equidigital number, since it uses as much as digits as its factorization.

16401789685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3280357942.

The product of its (nonzero) digits is 2903040, while the sum is 55.

The spelling of 16401789685 in words is "sixteen billion, four hundred one million, seven hundred eighty-nine thousand, six hundred eighty-five".