66247399 has 2 divisors, whose sum is σ = 66247400. Its totient is φ = 66247398.

The previous prime is 66247387. The next prime is 66247463. The reversal of 66247399 is 99374266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66247399 - 2⁷ = 66247271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66217399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33123699 + 33123700.

It is an arithmetic number, because the mean of its divisors is an integer number (33123700).

Almost surely, 2^66247399 is an apocalyptic number.

66247399 is a deficient number, since it is larger than the sum of its proper divisors (1).

66247399 is an equidigital number, since it uses as much as digits as its factorization.

66247399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 46.

The square root of 66247399 is about 8139.2505183217. The cubic root of 66247399 is about 404.6283213029.

The spelling of 66247399 in words is "sixty-six million, two hundred forty-seven thousand, three hundred ninety-nine".