166421401 has 8 divisors (see below), whose sum is σ = 172557000. Its totient is φ = 160312320.

The previous prime is 166421383. The next prime is 166421417. The reversal of 166421401 is 104124661.

It can be written as a sum of positive squares in 4 ways, for example, as 50751376 + 115670025 = 7124^2 + 10755^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166421401 - 2⁹ = 166420889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166421441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6631 + ... + 19411.

It is an arithmetic number, because the mean of its divisors is an integer number (21569625).

Almost surely, 2^166421401 is an apocalyptic number.

It is an amenable number.

166421401 is a deficient number, since it is larger than the sum of its proper divisors (6135599).

166421401 is a wasteful number, since it uses less digits than its factorization.

166421401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13259.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 166421401 is about 12900.4418916563. The cubic root of 166421401 is about 550.0511258259.

The spelling of 166421401 in words is "one hundred sixty-six million, four hundred twenty-one thousand, four hundred one".