66206642 has 4 divisors (see below), whose sum is σ = 99309966. Its totient is φ = 33103320.

The previous prime is 66206639. The next prime is 66206663. The reversal of 66206642 is 24660266.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 53597041 + 12609601 = 7321^2 + 3551^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66206599 and 66206608.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16551659 + ... + 16551662.

Almost surely, 2^66206642 is an apocalyptic number.

66206642 is a deficient number, since it is larger than the sum of its proper divisors (33103324).

66206642 is a wasteful number, since it uses less digits than its factorization.

66206642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33103323.

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 66206642 is about 8136.7464013572. The cubic root of 66206642 is about 404.5453252413.

The spelling of 66206642 in words is "sixty-six million, two hundred six thousand, six hundred forty-two".