164640066251 has 4 divisors (see below), whose sum is σ = 168143046432. Its totient is φ = 161137086072.

The previous prime is 164640066221. The next prime is 164640066257. The reversal of 164640066251 is 152660046461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 164640066251 - 2¹⁸ = 164639804107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 164640066199 and 164640066208.

It is not an unprimeable number, because it can be changed into a prime (164640066257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1751490020 + ... + 1751490113.

It is an arithmetic number, because the mean of its divisors is an integer number (42035761608).

Almost surely, 2^164640066251 is an apocalyptic number.

164640066251 is a deficient number, since it is larger than the sum of its proper divisors (3502980181).

164640066251 is an equidigital number, since it uses as much as digits as its factorization.

164640066251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3502980180.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 164640066251 in words is "one hundred sixty-four billion, six hundred forty million, sixty-six thousand, two hundred fifty-one".