16721427 has 4 divisors (see below), whose sum is σ = 22295240. Its totient is φ = 11147616.

The previous prime is 16721417. The next prime is 16721443. The reversal of 16721427 is 72412761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72412761 = 3 ⋅24137587.

It is not a de Polignac number, because 16721427 - 2¹¹ = 16719379 is a prime.

It is a super-2 number, since 2×16721427² = 559212241832658, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16721394 and 16721403.

It is not an unprimeable number, because it can be changed into a prime (16721407) 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, 2786902 + ... + 2786907.

It is an arithmetic number, because the mean of its divisors is an integer number (5573810).

Almost surely, 2^16721427 is an apocalyptic number.

16721427 is a deficient number, since it is larger than the sum of its proper divisors (5573813).

16721427 is an equidigital number, since it uses as much as digits as its factorization.

16721427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5573812.

The product of its digits is 4704, while the sum is 30.

The square root of 16721427 is about 4089.1841484580. The cubic root of 16721427 is about 255.7159273652.

The spelling of 16721427 in words is "sixteen million, seven hundred twenty-one thousand, four hundred twenty-seven".