16345681 has 16 divisors (see below), whose sum is σ = 18912960. Its totient is φ = 13970880.

The previous prime is 16345669. The next prime is 16345697. The reversal of 16345681 is 18654361.

16345681 = 1214² + 1215² + ... + 1224².

It is a happy number.

It is not a de Polignac number, because 16345681 - 2⁹ = 16345169 is a prime.

It is a super-2 number, since 2×16345681² = 534362574707522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16345631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40975 + ... + 41371.

It is an arithmetic number, because the mean of its divisors is an integer number (1182060).

Almost surely, 2^16345681 is an apocalyptic number.

16345681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16345681 is a deficient number, since it is larger than the sum of its proper divisors (2567279).

16345681 is a wasteful number, since it uses less digits than its factorization.

16345681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624.

The product of its digits is 17280, while the sum is 34.

The square root of 16345681 is about 4042.9792232956. The cubic root of 16345681 is about 253.7860071692.

The spelling of 16345681 in words is "sixteen million, three hundred forty-five thousand, six hundred eighty-one".