16991963 has 4 divisors (see below), whose sum is σ = 17730768. Its totient is φ = 16253160.

The previous prime is 16991951. The next prime is 16992007. The reversal of 16991963 is 36919961.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 16991963 - 2¹⁴ = 16975579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16997963) 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, 369368 + ... + 369413.

It is an arithmetic number, because the mean of its divisors is an integer number (4432692).

Almost surely, 2^16991963 is an apocalyptic number.

16991963 is a deficient number, since it is larger than the sum of its proper divisors (738805).

16991963 is an equidigital number, since it uses as much as digits as its factorization.

16991963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738804.

The product of its digits is 78732, while the sum is 44.

The square root of 16991963 is about 4122.1308809886. The cubic root of 16991963 is about 257.0876323058.

The spelling of 16991963 in words is "sixteen million, nine hundred ninety-one thousand, nine hundred sixty-three".