66201399 has 72 divisors (see below), whose sum is σ = 113533056. Its totient is φ = 37065600.

The previous prime is 66201361. The next prime is 66201407. The reversal of 66201399 is 99310266.

66201399 is a `hidden beast` number, since 66 + 201 + 399 = 666.

It is not a de Polignac number, because 66201399 - 2⁸ = 66201143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66201899) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1249057 + ... + 1249109.

It is an arithmetic number, because the mean of its divisors is an integer number (1576848).

Almost surely, 2^66201399 is an apocalyptic number.

66201399 is a deficient number, since it is larger than the sum of its proper divisors (47331657).

66201399 is a wasteful number, since it uses less digits than its factorization.

66201399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 66201399 is about 8136.4242146043. The cubic root of 66201399 is about 404.5346461157.

The spelling of 66201399 in words is "sixty-six million, two hundred one thousand, three hundred ninety-nine".