166421970 has 192 divisors, whose sum is σ = 518603904. Its totient is φ = 36495360.

The previous prime is 166421933. The next prime is 166421999. The reversal of 166421970 is 79124661.

166421970 = 228² + 229² + ... + 799².

166421970 is a `hidden beast` number, since 1 + 6 + 642 + 1 + 9 + 7 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 862194 + ... + 862386.

It is an arithmetic number, because the mean of its divisors is an integer number (2701062).

Almost surely, 2^166421970 is an apocalyptic number.

166421970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 166421970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (259301952).

166421970 is an abundant number, since it is smaller than the sum of its proper divisors (352181934).

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

166421970 is a wasteful number, since it uses less digits than its factorization.

166421970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297 (or 294 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 166421970 is about 12900.4639451455. The cubic root of 166421970 is about 550.0517527059.

The spelling of 166421970 in words is "one hundred sixty-six million, four hundred twenty-one thousand, nine hundred seventy".