66625663 has 4 divisors (see below), whose sum is σ = 71750728. Its totient is φ = 61500600.

The previous prime is 66625639. The next prime is 66625679. The reversal of 66625663 is 36652666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36652666 = 2 ⋅18326333.

It is a cyclic number.

It is not a de Polignac number, because 66625663 - 2⁵ = 66625631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66625693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2562513 + ... + 2562538.

It is an arithmetic number, because the mean of its divisors is an integer number (17937682).

Almost surely, 2^66625663 is an apocalyptic number.

66625663 is a deficient number, since it is larger than the sum of its proper divisors (5125065).

66625663 is a wasteful number, since it uses less digits than its factorization.

66625663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5125064.

The product of its digits is 233280, while the sum is 40.

The square root of 66625663 is about 8162.4544715422. The cubic root of 66625663 is about 405.3969851280.

The spelling of 66625663 in words is "sixty-six million, six hundred twenty-five thousand, six hundred sixty-three".