66696615 has 20 divisors (see below), whose sum is σ = 119560584. Its totient is φ = 35571312.

The previous prime is 66696599. The next prime is 66696629. The reversal of 66696615 is 51669666.

It is not a de Polignac number, because 66696615 - 2⁴ = 66696599 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 81937 + ... + 82746.

Almost surely, 2^66696615 is an apocalyptic number.

66696615 is a deficient number, since it is larger than the sum of its proper divisors (52863969).

66696615 is a wasteful number, since it uses less digits than its factorization.

66696615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164700 (or 164691 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 66696615 is about 8166.7995567419. The cubic root of 66696615 is about 405.5408412195.

It can be divided in two parts, 6669661 and 5, that added together give a palindrome (6669666).

The spelling of 66696615 in words is "sixty-six million, six hundred ninety-six thousand, six hundred fifteen".