66690346 has 4 divisors (see below), whose sum is σ = 100035522. Its totient is φ = 33345172.

The previous prime is 66690319. The next prime is 66690347. The reversal of 66690346 is 64309666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64309666 = 2 ⋅32154833.

It can be written as a sum of positive squares in only one way, i.e., 44023225 + 22667121 = 6635^2 + 4761^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66690299 and 66690308.

It is not an unprimeable number, because it can be changed into a prime (66690347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16672585 + ... + 16672588.

Almost surely, 2^66690346 is an apocalyptic number.

66690346 is a deficient number, since it is larger than the sum of its proper divisors (33345176).

66690346 is a wasteful number, since it uses less digits than its factorization.

66690346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33345175.

The product of its (nonzero) digits is 139968, while the sum is 40.

The square root of 66690346 is about 8166.4157376416. The cubic root of 66690346 is about 405.5281348516.

The spelling of 66690346 in words is "sixty-six million, six hundred ninety thousand, three hundred forty-six".