66398369 has 12 divisors (see below), whose sum is σ = 70513956. Its totient is φ = 62512128.

The previous prime is 66398363. The next prime is 66398399. The reversal of 66398369 is 96389366.

66398369 = 207² + 208² + ... + 592².

66398369 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 21669025 + 44729344 = 4655^2 + 6688^2 .

It is not a de Polignac number, because 66398369 - 2²⁴ = 49621153 is a prime.

It is a super-2 number, since 2×66398369² = 8817486811720322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66398363) 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 11 ways as a sum of consecutive naturals, for example, 69197 + ... + 70149.

It is an arithmetic number, because the mean of its divisors is an integer number (5876163).

Almost surely, 2^66398369 is an apocalyptic number.

It is an amenable number.

66398369 is a deficient number, since it is larger than the sum of its proper divisors (4115587).

66398369 is a wasteful number, since it uses less digits than its factorization.

66398369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184 (or 1165 counting only the distinct ones).

The product of its digits is 1259712, while the sum is 50.

The square root of 66398369 is about 8148.5194360694. The cubic root of 66398369 is about 404.9354548361.

The spelling of 66398369 in words is "sixty-six million, three hundred ninety-eight thousand, three hundred sixty-nine".