1825021221 has 4 divisors (see below), whose sum is σ = 2433361632. Its totient is φ = 1216680812.

The previous prime is 1825021067. The next prime is 1825021229. The reversal of 1825021221 is 1221205281.

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: 1221205281 = 3 ⋅407068427.

It is a cyclic number.

It is not a de Polignac number, because 1825021221 - 2¹⁴ = 1825004837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1825021191 and 1825021200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1825021229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 304170201 + ... + 304170206.

It is an arithmetic number, because the mean of its divisors is an integer number (608340408).

Almost surely, 2^1825021221 is an apocalyptic number.

It is an amenable number.

1825021221 is a deficient number, since it is larger than the sum of its proper divisors (608340411).

1825021221 is an equidigital number, since it uses as much as digits as its factorization.

1825021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608340410.

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 1825021221 is about 42720.2670988841. The cubic root of 1825021221 is about 1222.0509310331.

The spelling of 1825021221 in words is "one billion, eight hundred twenty-five million, twenty-one thousand, two hundred twenty-one".