3644697173881 has 3 divisors (see below), whose sum is σ = 3644699082991. Its totient is φ = 3644695264772.

The previous prime is 3644697173863. The next prime is 3644697173911. The reversal of 3644697173881 is 1883717964463.

The square root of 3644697173881 is 1909109.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1539934565481 + 2104762608400 = 1240941^2 + 1450780^2 .

It is not a de Polignac number, because 3644697173881 - 2¹¹ = 3644697171833 is a prime.

It is a super-2 number, since 2×3644697173881² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3644697173801) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 954555 + ... + 2863663.

Almost surely, 2^{3644697173881} is an apocalyptic number.

3644697173881 is the 1909109-th square number.

3644697173881 is the 954555-th centered octagonal number.

It is an amenable number.

3644697173881 is a deficient number, since it is larger than the sum of its proper divisors (1909110).

3644697173881 is an frugal number, since it uses more digits than its factorization.

3644697173881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3818218 (or 1909109 counting only the distinct ones).

The product of its digits is 146313216, while the sum is 67.

The spelling of 3644697173881 in words is "three trillion, six hundred forty-four billion, six hundred ninety-seven million, one hundred seventy-three thousand, eight hundred eighty-one".