66631338 has 48 divisors (see below), whose sum is σ = 152545536. Its totient is φ = 20986560.

The previous prime is 66631319. The next prime is 66631343. The reversal of 66631338 is 83313666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22606 + ... + 25382.

It is an arithmetic number, because the mean of its divisors is an integer number (3178032).

Almost surely, 2^66631338 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66631338, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76272768).

66631338 is an abundant number, since it is smaller than the sum of its proper divisors (85914198).

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

66631338 is a wasteful number, since it uses less digits than its factorization.

66631338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2859 (or 2856 counting only the distinct ones).

The product of its digits is 46656, while the sum is 36.

The square root of 66631338 is about 8162.8020924190. The cubic root of 66631338 is about 405.4084950201.

It can be divided in two parts, 6663 and 1338, that added together give a triangular number (8001 = T₁₂₆).

The spelling of 66631338 in words is "sixty-six million, six hundred thirty-one thousand, three hundred thirty-eight".