66390426 has 12 divisors (see below), whose sum is σ = 143845962. Its totient is φ = 22130136.

The previous prime is 66390421. The next prime is 66390449. The reversal of 66390426 is 62409366.

It can be written as a sum of positive squares in only one way, i.e., 62964225 + 3426201 = 7935^2 + 1851^2 .

It is a super-2 number, since 2×66390426² = 8815377328922952, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66390421) 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, 1844161 + ... + 1844196.

Almost surely, 2^66390426 is an apocalyptic number.

66390426 is an abundant number, since it is smaller than the sum of its proper divisors (77455536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66390426 is a wasteful number, since it uses less digits than its factorization.

66390426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3688365 (or 3688362 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 66390426 is about 8148.0320323376. The cubic root of 66390426 is about 404.9193071976.

The spelling of 66390426 in words is "sixty-six million, three hundred ninety thousand, four hundred twenty-six".