1890521 has 2 divisors, whose sum is σ = 1890522. Its totient is φ = 1890520.

The previous prime is 1890509. The next prime is 1890523. The reversal of 1890521 is 1250981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1784896 + 105625 = 1336^2 + 325^2 .

It is an emirp because it is prime and its reverse (1250981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1890521 - 2¹⁰ = 1889497 is a prime.

Together with 1890523, it forms a pair of twin primes.

It is a Chen prime.

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

It is not a weakly prime, because it can be changed into another prime (1890523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945260 + 945261.

It is an arithmetic number, because the mean of its divisors is an integer number (945261).

2^1890521 is an apocalyptic number.

It is an amenable number.

1890521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1890521 is an equidigital number, since it uses as much as digits as its factorization.

1890521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 1890521 is about 1374.9621812981. The cubic root of 1890521 is about 123.6499187423.

The spelling of 1890521 in words is "one million, eight hundred ninety thousand, five hundred twenty-one".