66953918 has 4 divisors (see below), whose sum is σ = 100430880. Its totient is φ = 33476958.

The previous prime is 66953917. The next prime is 66953927. The reversal of 66953918 is 81935966.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66953917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16738478 + ... + 16738481.

It is an arithmetic number, because the mean of its divisors is an integer number (25107720).

Almost surely, 2^66953918 is an apocalyptic number.

66953918 is a deficient number, since it is larger than the sum of its proper divisors (33476962).

66953918 is a wasteful number, since it uses less digits than its factorization.

66953918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33476961.

The product of its digits is 349920, while the sum is 47.

The square root of 66953918 is about 8182.5373815217. The cubic root of 66953918 is about 406.0616721411.

The spelling of 66953918 in words is "sixty-six million, nine hundred fifty-three thousand, nine hundred eighteen".