66254399 has 4 divisors (see below), whose sum is σ = 67504536. Its totient is φ = 65004264.

The previous prime is 66254341. The next prime is 66254407. The reversal of 66254399 is 99345266.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66254399 - 2²⁰ = 65205823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66254339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 624989 + ... + 625094.

It is an arithmetic number, because the mean of its divisors is an integer number (16876134).

Almost surely, 2^66254399 is an apocalyptic number.

66254399 is a deficient number, since it is larger than the sum of its proper divisors (1250137).

66254399 is a wasteful number, since it uses less digits than its factorization.

66254399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250136.

The product of its digits is 349920, while the sum is 44.

The square root of 66254399 is about 8139.6805219861. The cubic root of 66254399 is about 404.6425724208.

The spelling of 66254399 in words is "sixty-six million, two hundred fifty-four thousand, three hundred ninety-nine".