16721947 has 8 divisors (see below), whose sum is σ = 18420480. Its totient is φ = 15053160.

The previous prime is 16721941. The next prime is 16721953. The reversal of 16721947 is 74912761.

It is an interprime number because it is at equal distance from previous prime (16721941) and next prime (16721953).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16721947 - 2⁷ = 16721819 is a prime.

It is a super-2 number, since 2×16721947² = 559247022941618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16721941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6247 + ... + 8512.

It is an arithmetic number, because the mean of its divisors is an integer number (2302560).

Almost surely, 2^16721947 is an apocalyptic number.

16721947 is a deficient number, since it is larger than the sum of its proper divisors (1698533).

16721947 is a wasteful number, since it uses less digits than its factorization.

16721947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14873.

The product of its digits is 21168, while the sum is 37.

The square root of 16721947 is about 4089.2477303289. The cubic root of 16721947 is about 255.7185780741.

The spelling of 16721947 in words is "sixteen million, seven hundred twenty-one thousand, nine hundred forty-seven".