66403811 has 4 divisors (see below), whose sum is σ = 66462072. Its totient is φ = 66345552.

The previous prime is 66403747. The next prime is 66403847. The reversal of 66403811 is 11830466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11830466 = 2 ⋅5915233.

It is a cyclic number.

It is not a de Polignac number, because 66403811 - 2⁶ = 66403747 is a prime.

It is a super-2 number, since 2×66403811² = 8818932230647442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66403861) 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, 27386 + ... + 29711.

It is an arithmetic number, because the mean of its divisors is an integer number (16615518).

Almost surely, 2^66403811 is an apocalyptic number.

66403811 is a deficient number, since it is larger than the sum of its proper divisors (58261).

66403811 is a wasteful number, since it uses less digits than its factorization.

66403811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58260.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 66403811 is about 8148.8533549206. The cubic root of 66403811 is about 404.9465173495.

The spelling of 66403811 in words is "sixty-six million, four hundred three thousand, eight hundred eleven".