16681501 has 4 divisors (see below), whose sum is σ = 16695072. Its totient is φ = 16667932.

The previous prime is 16681499. The next prime is 16681507. The reversal of 16681501 is 10518661.

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 16681501 - 2¹ = 16681499 is a prime.

It is a super-2 number, since 2×16681501² = 556544951226002, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16681501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16681507) 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, 4735 + ... + 7468.

It is an arithmetic number, because the mean of its divisors is an integer number (4173768).

Almost surely, 2^16681501 is an apocalyptic number.

It is an amenable number.

16681501 is a deficient number, since it is larger than the sum of its proper divisors (13571).

16681501 is a wasteful number, since it uses less digits than its factorization.

16681501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13570.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 16681501 is about 4084.2993279142. The cubic root of 16681501 is about 255.5122395884.

The spelling of 16681501 in words is "sixteen million, six hundred eighty-one thousand, five hundred one".