1821490565 has 8 divisors (see below), whose sum is σ = 2196885240. Its totient is φ = 1449794752.

The previous prime is 1821490507. The next prime is 1821490577. The reversal of 1821490565 is 5650941281.

It can be written as a sum of positive squares in 4 ways, for example, as 122567041 + 1698923524 = 11071^2 + 41218^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1821490565 - 2¹⁴ = 1821474181 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 923630 + ... + 925599.

It is an arithmetic number, because the mean of its divisors is an integer number (274610655).

Almost surely, 2^1821490565 is an apocalyptic number.

It is an amenable number.

1821490565 is a deficient number, since it is larger than the sum of its proper divisors (375394675).

1821490565 is a wasteful number, since it uses less digits than its factorization.

1821490565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1849431.

The product of its (nonzero) digits is 86400, while the sum is 41.

The square root of 1821490565 is about 42678.9241312384. The cubic root of 1821490565 is about 1221.2623690991.

The spelling of 1821490565 in words is "one billion, eight hundred twenty-one million, four hundred ninety thousand, five hundred sixty-five".