66129620 has 12 divisors (see below), whose sum is σ = 138872244. Its totient is φ = 26451840.

The previous prime is 66129607. The next prime is 66129631. The reversal of 66129620 is 2692166.

It can be written as a sum of positive squares in 2 ways, for example, as 23697424 + 42432196 = 4868^2 + 6514^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1653221 + ... + 1653260.

It is an arithmetic number, because the mean of its divisors is an integer number (11572687).

Almost surely, 2^66129620 is an apocalyptic number.

It is an amenable number.

66129620 is an abundant number, since it is smaller than the sum of its proper divisors (72742624).

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

66129620 is a wasteful number, since it uses less digits than its factorization.

66129620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3306490 (or 3306488 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 66129620 is about 8132.0120511470. The cubic root of 66129620 is about 404.3883874080.

The spelling of 66129620 in words is "sixty-six million, one hundred twenty-nine thousand, six hundred twenty".