16399697 has 4 divisors (see below), whose sum is σ = 16440996. Its totient is φ = 16358400.

The previous prime is 16399681. The next prime is 16399729. The reversal of 16399697 is 79699361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79699361 = 7 ⋅11385623.

It can be written as a sum of positive squares in 2 ways, for example, as 15555136 + 844561 = 3944^2 + 919^2 .

It is a cyclic number.

It is not a de Polignac number, because 16399697 - 2⁴ = 16399681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16393697) 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, 20048 + ... + 20849.

It is an arithmetic number, because the mean of its divisors is an integer number (4110249).

Almost surely, 2^16399697 is an apocalyptic number.

It is an amenable number.

16399697 is a deficient number, since it is larger than the sum of its proper divisors (41299).

16399697 is an equidigital number, since it uses as much as digits as its factorization.

16399697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41298.

The product of its digits is 551124, while the sum is 50.

The square root of 16399697 is about 4049.6539358320. The cubic root of 16399697 is about 254.0652538651.

The spelling of 16399697 in words is "sixteen million, three hundred ninety-nine thousand, six hundred ninety-seven".