164421999 has 18 divisors (see below), whose sum is σ = 276274440. Its totient is φ = 93955176.

The previous prime is 164421979. The next prime is 164422003. The reversal of 164421999 is 999124461.

164421999 is a `hidden beast` number, since 16 + 442 + 199 + 9 = 666.

It is not a de Polignac number, because 164421999 - 2¹¹ = 164419951 is a prime.

It is a super-3 number, since 3×164421999³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164421919) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 185979 + ... + 186860.

It is an arithmetic number, because the mean of its divisors is an integer number (15348580).

Almost surely, 2^164421999 is an apocalyptic number.

164421999 is a deficient number, since it is larger than the sum of its proper divisors (111852441).

164421999 is a wasteful number, since it uses less digits than its factorization.

164421999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372859 (or 372849 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 164421999 is about 12822.7141822627. The cubic root of 164421999 is about 547.8394567188.

The spelling of 164421999 in words is "one hundred sixty-four million, four hundred twenty-one thousand, nine hundred ninety-nine".