66173720 has 16 divisors (see below), whose sum is σ = 148890960. Its totient is φ = 26469472.

The previous prime is 66173677. The next prime is 66173743. The reversal of 66173720 is 2737166.

It is a super-2 number, since 2×66173720² = 8757922437276800, which contains 22 as substring.

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, 827132 + ... + 827211.

It is an arithmetic number, because the mean of its divisors is an integer number (9305685).

Almost surely, 2^66173720 is an apocalyptic number.

It is an amenable number.

66173720 is an abundant number, since it is smaller than the sum of its proper divisors (82717240).

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

66173720 is a wasteful number, since it uses less digits than its factorization.

66173720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1654354 (or 1654350 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 66173720 is about 8134.7231053060. The cubic root of 66173720 is about 404.4782592139.

The spelling of 66173720 in words is "sixty-six million, one hundred seventy-three thousand, seven hundred twenty".