1881521 has 2 divisors, whose sum is σ = 1881522. Its totient is φ = 1881520.

The previous prime is 1881511. The next prime is 1881533. The reversal of 1881521 is 1251881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1860496 + 21025 = 1364^2 + 145^2 .

It is an emirp because it is prime and its reverse (1251881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1881521 - 2¹⁰ = 1880497 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1881511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 940760 + 940761.

It is an arithmetic number, because the mean of its divisors is an integer number (940761).

2^1881521 is an apocalyptic number.

It is an amenable number.

1881521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881521 is an equidigital number, since it uses as much as digits as its factorization.

1881521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 640, while the sum is 26.

The square root of 1881521 is about 1371.6854595715. The cubic root of 1881521 is about 123.4533909254.

Subtracting from 1881521 its product of digits (640), we obtain a palindrome (1880881).

The spelling of 1881521 in words is "one million, eight hundred eighty-one thousand, five hundred twenty-one".