1817402161 has 9 divisors (see below), whose sum is σ = 1841897131. Its totient is φ = 1793230384.

The previous prime is 1817402159. The next prime is 1817402173. The reversal of 1817402161 is 1612047181.

The square root of 1817402161 is 42631.

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., 348979761 + 1468422400 = 18681^2 + 38320^2 .

It is not a de Polignac number, because 1817402161 - 2¹ = 1817402159 is a prime.

It is a super-2 number, since 2×1817402161² = 6605901229614939842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1817402861) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3793920 + ... + 3794398.

Almost surely, 2^1817402161 is an apocalyptic number.

1817402161 is the 42631-st square number.

1817402161 is the 21316-th centered octagonal number.

It is an amenable number.

1817402161 is a deficient number, since it is larger than the sum of its proper divisors (24494970).

1817402161 is an frugal number, since it uses more digits than its factorization.

1817402161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136 (or 568 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 31.

The cubic root of 1817402161 is about 1220.3479615281.

The spelling of 1817402161 in words is "one billion, eight hundred seventeen million, four hundred two thousand, one hundred sixty-one".