166221521670120 has 128 divisors (see below), whose sum is σ = 571959770054400. Its totient is φ = 37856329998336.

The previous prime is 166221521670101. The next prime is 166221521670131. The reversal of 166221521670120 is 21076125122661.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 356956425 + ... + 357421784.

It is an arithmetic number, because the mean of its divisors is an integer number (4468435703550).

Almost surely, 2^{166221521670120} is an apocalyptic number.

166221521670120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166221521670120 is an abundant number, since it is smaller than the sum of its proper divisors (405738248384280).

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

166221521670120 is a wasteful number, since it uses less digits than its factorization.

166221521670120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714378507 (or 714378503 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

Adding to 166221521670120 its reverse (21076125122661), we get a palindrome (187297646792781).

The spelling of 166221521670120 in words is "one hundred sixty-six trillion, two hundred twenty-one billion, five hundred twenty-one million, six hundred seventy thousand, one hundred twenty".