164641340421 has 30 divisors (see below), whose sum is σ = 251290204550. Its totient is φ = 107425438704.

The previous prime is 164641340419. The next prime is 164641340447. The reversal of 164641340421 is 124043146461.

164641340421 is a `hidden beast` number, since 1 + 6 + 4 + 641 + 3 + 4 + 0 + 4 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 146547324225 + 18094016196 = 382815^2 + 134514^2 .

It is not a de Polignac number, because 164641340421 - 2¹ = 164641340419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164641340401) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 281146 + ... + 639003.

Almost surely, 2^164641340421 is an apocalyptic number.

It is an amenable number.

164641340421 is a deficient number, since it is larger than the sum of its proper divisors (86648864129).

164641340421 is an frugal number, since it uses more digits than its factorization.

164641340421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920255 (or 920199 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

Adding to 164641340421 its reverse (124043146461), we get a palindrome (288684486882).

The spelling of 164641340421 in words is "one hundred sixty-four billion, six hundred forty-one million, three hundred forty thousand, four hundred twenty-one".