66816402 has 16 divisors (see below), whose sum is σ = 134155872. Its totient is φ = 22184960.

The previous prime is 66816397. The next prime is 66816427. The reversal of 66816402 is 20461866.

It is a happy number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20124 + ... + 23207.

It is an arithmetic number, because the mean of its divisors is an integer number (8384742).

Almost surely, 2^66816402 is an apocalyptic number.

66816402 is an abundant number, since it is smaller than the sum of its proper divisors (67339470).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66816402 is a wasteful number, since it uses less digits than its factorization.

66816402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43593.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 66816402 is about 8174.1300454544. The cubic root of 66816402 is about 405.7834795574.

The spelling of 66816402 in words is "sixty-six million, eight hundred sixteen thousand, four hundred two".