2171653164409 has 15 divisors (see below), whose sum is σ = 2226152337407. Its totient is φ = 2118488185128.

The previous prime is 2171653164407. The next prime is 2171653164437. The reversal of 2171653164409 is 9044613561712.

The square root of 2171653164409 is 1473653.

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

It can be written as a sum of positive squares in only one way, i.e., 1053076178025 + 1118576986384 = 1026195^2 + 1057628^2 .

It is not a de Polignac number, because 2171653164409 - 2¹ = 2171653164407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2171653164407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2724783999 + ... + 2724784795.

Almost surely, 2^{2171653164409} is an apocalyptic number.

2171653164409 is the 1473653-rd square number.

2171653164409 is the 736827-th centered octagonal number.

It is an amenable number.

2171653164409 is a deficient number, since it is larger than the sum of its proper divisors (54499172998).

2171653164409 is an frugal number, since it uses more digits than its factorization.

2171653164409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1766 (or 840 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 49.

Multiplying 2171653164409 by its sum of digits (49), we get a square (106411005056041 = 10315571²).

The spelling of 2171653164409 in words is "two trillion, one hundred seventy-one billion, six hundred fifty-three million, one hundred sixty-four thousand, four hundred nine".