1890121 has 2 divisors, whose sum is σ = 1890122. Its totient is φ = 1890120.

The previous prime is 1890113. The next prime is 1890149. The reversal of 1890121 is 1210981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1863225 + 26896 = 1365^2 + 164^2 .

It is a cyclic number.

It is not a de Polignac number, because 1890121 - 2³ = 1890113 is a prime.

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

It is equal to p₁₄₁₃₄₉ and since 1890121 and 141349 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 1890092 and 1890101.

It is not a weakly prime, because it can be changed into another prime (1890221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945060 + 945061.

It is an arithmetic number, because the mean of its divisors is an integer number (945061).

2^1890121 is an apocalyptic number.

It is an amenable number.

1890121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1890121 is an equidigital number, since it uses as much as digits as its factorization.

1890121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 1890121 is about 1374.8167150570. The cubic root of 1890121 is about 123.6411974328.

The spelling of 1890121 in words is "one million, eight hundred ninety thousand, one hundred twenty-one".