164293219561 has 27 divisors (see below), whose sum is σ = 176922638373. Its totient is φ = 152534161920.

The previous prime is 164293219513. The next prime is 164293219567. The reversal of 164293219561 is 165912392461.

The square root of 164293219561 is 405331.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 20045179561 + 144248040000 = 141581^2 + 379800^2 .

It is not a de Polignac number, because 164293219561 - 2¹¹ = 164293217513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164293219567) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 778640746 + ... + 778640956.

Almost surely, 2^164293219561 is an apocalyptic number.

164293219561 is the 405331-st square number.

164293219561 is the 202666-th centered octagonal number.

It is an amenable number.

164293219561 is a deficient number, since it is larger than the sum of its proper divisors (12629418812).

164293219561 is an frugal number, since it uses more digits than its factorization.

164293219561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682 (or 341 counting only the distinct ones).

The product of its digits is 699840, while the sum is 49.

Multiplying 164293219561 by its sum of digits (49), we get a square (8050367758489 = 2837317²).

The spelling of 164293219561 in words is "one hundred sixty-four billion, two hundred ninety-three million, two hundred nineteen thousand, five hundred sixty-one".