66193893 has 6 divisors (see below), whose sum is σ = 95613414. Its totient is φ = 44129256.

The previous prime is 66193889. The next prime is 66193901. The reversal of 66193893 is 39839166.

It can be written as a sum of positive squares in only one way, i.e., 58476609 + 7717284 = 7647^2 + 2778^2 .

It is not a de Polignac number, because 66193893 - 2² = 66193889 is a prime.

It is a super-4 number, since 4×66193893⁴ (a number of 32 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66193843) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3677430 + ... + 3677447.

It is an arithmetic number, because the mean of its divisors is an integer number (15935569).

Almost surely, 2^66193893 is an apocalyptic number.

It is an amenable number.

66193893 is a deficient number, since it is larger than the sum of its proper divisors (29419521).

66193893 is a wasteful number, since it uses less digits than its factorization.

66193893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7354883 (or 7354880 counting only the distinct ones).

The product of its digits is 209952, while the sum is 45.

The square root of 66193893 is about 8135.9629423935. The cubic root of 66193893 is about 404.5193566512.

The spelling of 66193893 in words is "sixty-six million, one hundred ninety-three thousand, eight hundred ninety-three".