1816652521 has 4 divisors (see below), whose sum is σ = 1923514452. Its totient is φ = 1709790592.

The previous prime is 1816652489. The next prime is 1816652531. The reversal of 1816652521 is 1252566181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1252566181 = 409 ⋅3062509.

It can be written as a sum of positive squares in 2 ways, for example, as 864066025 + 952586496 = 29395^2 + 30864^2 .

It is a cyclic number.

It is not a de Polignac number, because 1816652521 - 2⁵ = 1816652489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1816652531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53430940 + ... + 53430973.

It is an arithmetic number, because the mean of its divisors is an integer number (480878613).

Almost surely, 2^1816652521 is an apocalyptic number.

It is an amenable number.

1816652521 is a deficient number, since it is larger than the sum of its proper divisors (106861931).

1816652521 is a wasteful number, since it uses less digits than its factorization.

1816652521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106861930.

The product of its digits is 28800, while the sum is 37.

The square root of 1816652521 is about 42622.2068996902. The cubic root of 1816652521 is about 1220.1801492013.

The spelling of 1816652521 in words is "one billion, eight hundred sixteen million, six hundred fifty-two thousand, five hundred twenty-one".