66616642 has 8 divisors (see below), whose sum is σ = 105802956. Its totient is φ = 31348992.

The previous prime is 66616631. The next prime is 66616651. The reversal of 66616642 is 24661666.

It can be written as a sum of positive squares in 2 ways, for example, as 66243321 + 373321 = 8139^2 + 611^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979623 + ... + 979690.

Almost surely, 2^66616642 is an apocalyptic number.

66616642 is a deficient number, since it is larger than the sum of its proper divisors (39186314).

66616642 is a wasteful number, since it uses less digits than its factorization.

66616642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959332.

The product of its digits is 62208, while the sum is 37.

The square root of 66616642 is about 8161.9018616987. The cubic root of 66616642 is about 405.3786876177.

It can be divided in two parts, 6661664 and 2, that added together give a palindrome (6661666).

The spelling of 66616642 in words is "sixty-six million, six hundred sixteen thousand, six hundred forty-two".