66040021738 has 8 divisors (see below), whose sum is σ = 100929089988. Its totient is φ = 32396991744.

The previous prime is 66040021681. The next prime is 66040021753. The reversal of 66040021738 is 83712004066.

It can be written as a sum of positive squares in 2 ways, for example, as 55831546369 + 10208475369 = 236287^2 + 101037^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×66040021738² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66040021697 and 66040021706.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311509431 + ... + 311509642.

Almost surely, 2^66040021738 is an apocalyptic number.

66040021738 is a deficient number, since it is larger than the sum of its proper divisors (34889068250).

66040021738 is a wasteful number, since it uses less digits than its factorization.

66040021738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623019128.

The product of its (nonzero) digits is 48384, while the sum is 37.

The spelling of 66040021738 in words is "sixty-six billion, forty million, twenty-one thousand, seven hundred thirty-eight".