164406421 has 2 divisors, whose sum is σ = 164406422. Its totient is φ = 164406420.

The previous prime is 164406413. The next prime is 164406443. The reversal of 164406421 is 124604461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117483921 + 46922500 = 10839^2 + 6850^2 .

It is a cyclic number.

It is not a de Polignac number, because 164406421 - 2³ = 164406413 is a prime.

It is a super-3 number, since 3×164406421³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 164406421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164406401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82203210 + 82203211.

It is an arithmetic number, because the mean of its divisors is an integer number (82203211).

Almost surely, 2^164406421 is an apocalyptic number.

It is an amenable number.

164406421 is a deficient number, since it is larger than the sum of its proper divisors (1).

164406421 is an equidigital number, since it uses as much as digits as its factorization.

164406421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 164406421 is about 12822.1067301750. The cubic root of 164406421 is about 547.8221546695.

The spelling of 164406421 in words is "one hundred sixty-four million, four hundred six thousand, four hundred twenty-one".