1810090221 has 4 divisors (see below), whose sum is σ = 2413453632. Its totient is φ = 1206726812.

The previous prime is 1810090207. The next prime is 1810090229. The reversal of 1810090221 is 1220900181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1220900181 = 3 ⋅406966727.

It is a cyclic number.

It is not a de Polignac number, because 1810090221 - 2⁵ = 1810090189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1810090191 and 1810090200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1810090229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301681701 + ... + 301681706.

It is an arithmetic number, because the mean of its divisors is an integer number (603363408).

Almost surely, 2^1810090221 is an apocalyptic number.

It is an amenable number.

1810090221 is a deficient number, since it is larger than the sum of its proper divisors (603363411).

1810090221 is an equidigital number, since it uses as much as digits as its factorization.

1810090221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603363410.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 1810090221 is about 42545.1550825708. The cubic root of 1810090221 is about 1218.7091562696.

The spelling of 1810090221 in words is "one billion, eight hundred ten million, ninety thousand, two hundred twenty-one".