1812164281 has 4 divisors (see below), whose sum is σ = 1861141732. Its totient is φ = 1763186832.

The previous prime is 1812164279. The next prime is 1812164293. The reversal of 1812164281 is 1824612181.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1302127225 + 510037056 = 36085^2 + 22584^2 .

It is a cyclic number.

It is not a de Polignac number, because 1812164281 - 2¹ = 1812164279 is a prime.

It is a super-2 number, since 2×1812164281² = 6567878762664493922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1812164251) 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, 24488670 + ... + 24488743.

It is an arithmetic number, because the mean of its divisors is an integer number (465285433).

Almost surely, 2^1812164281 is an apocalyptic number.

It is an amenable number.

1812164281 is a deficient number, since it is larger than the sum of its proper divisors (48977451).

1812164281 is an equidigital number, since it uses as much as digits as its factorization.

1812164281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48977450.

The product of its digits is 6144, while the sum is 34.

The square root of 1812164281 is about 42569.5229125251. The cubic root of 1812164281 is about 1219.1744574033.

The spelling of 1812164281 in words is "one billion, eight hundred twelve million, one hundred sixty-four thousand, two hundred eighty-one".