16991474 has 4 divisors (see below), whose sum is σ = 25487214. Its totient is φ = 8495736.

The previous prime is 16991467. The next prime is 16991497. The reversal of 16991474 is 47419961.

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., 15155449 + 1836025 = 3893^2 + 1355^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4247867 + ... + 4247870.

Almost surely, 2^16991474 is an apocalyptic number.

16991474 is a deficient number, since it is larger than the sum of its proper divisors (8495740).

16991474 is an equidigital number, since it uses as much as digits as its factorization.

16991474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8495739.

The product of its digits is 54432, while the sum is 41.

The square root of 16991474 is about 4122.0715665791. The cubic root of 16991474 is about 257.0851660995.

The spelling of 16991474 in words is "sixteen million, nine hundred ninety-one thousand, four hundred seventy-four".