16607681 has 4 divisors (see below), whose sum is σ = 16841664. Its totient is φ = 16373700.

The previous prime is 16607671. The next prime is 16607687. The reversal of 16607681 is 18670661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16607681 - 2¹⁰ = 16606657 is a prime.

It is a super-2 number, since 2×16607681² = 551630136395522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16607687) 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, 116885 + ... + 117026.

It is an arithmetic number, because the mean of its divisors is an integer number (4210416).

Almost surely, 2^16607681 is an apocalyptic number.

It is an amenable number.

16607681 is a deficient number, since it is larger than the sum of its proper divisors (233983).

16607681 is an equidigital number, since it uses as much as digits as its factorization.

16607681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233982.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 16607681 is about 4075.2522621305. The cubic root of 16607681 is about 255.1347794486.

The spelling of 16607681 in words is "sixteen million, six hundred seven thousand, six hundred eighty-one".