66621198 has 32 divisors (see below), whose sum is σ = 161236224. Its totient is φ = 17914752.

The previous prime is 66621169. The next prime is 66621199. The reversal of 66621198 is 89112666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66621199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45940 + ... + 47367.

It is an arithmetic number, because the mean of its divisors is an integer number (5038632).

Almost surely, 2^66621198 is an apocalyptic number.

66621198 is an abundant number, since it is smaller than the sum of its proper divisors (94615026).

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

66621198 is a wasteful number, since it uses less digits than its factorization.

66621198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93336.

The product of its digits is 31104, while the sum is 39.

The square root of 66621198 is about 8162.1809585429. The cubic root of 66621198 is about 405.3879288680.

The spelling of 66621198 in words is "sixty-six million, six hundred twenty-one thousand, one hundred ninety-eight".