66253805 has 4 divisors (see below), whose sum is σ = 79504572. Its totient is φ = 53003040.

The previous prime is 66253799. The next prime is 66253819. The reversal of 66253805 is 50835266.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50835266 = 2 ⋅25417633.

It can be written as a sum of positive squares in 2 ways, for example, as 33512521 + 32741284 = 5789^2 + 5722^2 .

It is not a de Polignac number, because 66253805 - 2⁸ = 66253549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 6625376 + ... + 6625385.

It is an arithmetic number, because the mean of its divisors is an integer number (19876143).

Almost surely, 2^66253805 is an apocalyptic number.

It is an amenable number.

66253805 is a deficient number, since it is larger than the sum of its proper divisors (13250767).

66253805 is a wasteful number, since it uses less digits than its factorization.

66253805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13250766.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 66253805 is about 8139.6440339858. The cubic root of 66253805 is about 404.6413631506.

The spelling of 66253805 in words is "sixty-six million, two hundred fifty-three thousand, eight hundred five".