66439908 has 36 divisors (see below), whose sum is σ = 168206220. Its totient is φ = 22112256.

The previous prime is 66439873. The next prime is 66439963. The reversal of 66439908 is 80993466.

It can be written as a sum of positive squares in 2 ways, for example, as 49449024 + 16990884 = 7032^2 + 4122^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×66439908² = 8828522750096928, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34228 + ... + 36116.

It is an arithmetic number, because the mean of its divisors is an integer number (4672395).

Almost surely, 2^66439908 is an apocalyptic number.

It is an amenable number.

66439908 is an abundant number, since it is smaller than the sum of its proper divisors (101766312).

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

66439908 is a wasteful number, since it uses less digits than its factorization.

66439908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2876 (or 2871 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 66439908 is about 8151.0679054956. The cubic root of 66439908 is about 405.0198801398.

The spelling of 66439908 in words is "sixty-six million, four hundred thirty-nine thousand, nine hundred eight".