66397511 has 4 divisors (see below), whose sum is σ = 67810272. Its totient is φ = 64984752.

The previous prime is 66397453. The next prime is 66397531. The reversal of 66397511 is 11579366.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11579366 = 2 ⋅5789683.

It is a cyclic number.

It is not a de Polignac number, because 66397511 - 2¹⁴ = 66381127 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 (66397531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 706310 + ... + 706403.

It is an arithmetic number, because the mean of its divisors is an integer number (16952568).

Almost surely, 2^66397511 is an apocalyptic number.

66397511 is a deficient number, since it is larger than the sum of its proper divisors (1412761).

66397511 is a wasteful number, since it uses less digits than its factorization.

66397511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1412760.

The product of its digits is 34020, while the sum is 38.

The square root of 66397511 is about 8148.4667882983. The cubic root of 66397511 is about 404.9337106361.

The spelling of 66397511 in words is "sixty-six million, three hundred ninety-seven thousand, five hundred eleven".