66721592 has 16 divisors (see below), whose sum is σ = 142974960. Its totient is φ = 28594944.

The previous prime is 66721591. The next prime is 66721601. The reversal of 66721592 is 29512766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66721591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 595673 + ... + 595784.

It is an arithmetic number, because the mean of its divisors is an integer number (8935935).

Almost surely, 2^66721592 is an apocalyptic number.

It is an amenable number.

66721592 is an abundant number, since it is smaller than the sum of its proper divisors (76253368).

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

66721592 is a wasteful number, since it uses less digits than its factorization.

66721592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191470 (or 1191466 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 66721592 is about 8168.3285928028. The cubic root of 66721592 is about 405.5914581283.

The spelling of 66721592 in words is "sixty-six million, seven hundred twenty-one thousand, five hundred ninety-two".