1812121 has 2 divisors, whose sum is σ = 1812122. Its totient is φ = 1812120.

The previous prime is 1812103. The next prime is 1812131. The reversal of 1812121 is 1212181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1784896 + 27225 = 1336^2 + 165^2 .

It is a cyclic number.

It is not a de Polignac number, because 1812121 - 2⁵ = 1812089 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 1812095 and 1812104.

It is not a weakly prime, because it can be changed into another prime (1812131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 906060 + 906061.

It is an arithmetic number, because the mean of its divisors is an integer number (906061).

2^1812121 is an apocalyptic number.

It is an amenable number.

1812121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1812121 is an equidigital number, since it uses as much as digits as its factorization.

1812121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32, while the sum is 16.

The square root of 1812121 is about 1346.1504373583. The cubic root of 1812121 is about 121.9164751236.

The spelling of 1812121 in words is "one million, eight hundred twelve thousand, one hundred twenty-one".