2521021636 has 12 divisors (see below), whose sum is σ = 5042043328. Its totient is φ = 1080437832.

The previous prime is 2521021627. The next prime is 2521021703. The reversal of 2521021636 is 6361201252.

2521021636 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 90036487 = 2521021636 / (2 + 5 + 2 + 1 + 0 + 2 + 1 + 6 + 3 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45018216 + ... + 45018271.

Almost surely, 2^2521021636 is an apocalyptic number.

It is an amenable number.

2521021636 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2521021636 is a wasteful number, since it uses less digits than its factorization.

2521021636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90036498 (or 90036496 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 2521021636 is about 50209.7762990436. The cubic root of 2521021636 is about 1361.0022953146.

Adding to 2521021636 its reverse (6361201252), we get a palindrome (8882222888).

The spelling of 2521021636 in words is "two billion, five hundred twenty-one million, twenty-one thousand, six hundred thirty-six".