66167820 has 48 divisors (see below), whose sum is σ = 205857120. Its totient is φ = 17644608.

The previous prime is 66167819. The next prime is 66167839. The reversal of 66167820 is 2876166.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60727 + ... + 61806.

It is an arithmetic number, because the mean of its divisors is an integer number (4288690).

Almost surely, 2^66167820 is an apocalyptic number.

66167820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66167820 is an abundant number, since it is smaller than the sum of its proper divisors (139689300).

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

66167820 is a wasteful number, since it uses less digits than its factorization.

66167820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122551 (or 122543 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66167820 is about 8134.3604542705. The cubic root of 66167820 is about 404.4662378624.

The spelling of 66167820 in words is "sixty-six million, one hundred sixty-seven thousand, eight hundred twenty".