2520221021 has 4 divisors (see below), whose sum is σ = 2629795872. Its totient is φ = 2410646172.

The previous prime is 2520220979. The next prime is 2520221057. The reversal of 2520221021 is 1201220252.

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.

It is a cyclic number.

It is not a de Polignac number, because 2520221021 - 2¹⁰ = 2520219997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2520226021) 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, 54787391 + ... + 54787436.

It is an arithmetic number, because the mean of its divisors is an integer number (657448968).

Almost surely, 2^2520221021 is an apocalyptic number.

It is an amenable number.

2520221021 is a deficient number, since it is larger than the sum of its proper divisors (109574851).

2520221021 is a wasteful number, since it uses less digits than its factorization.

2520221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109574850.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 2520221021 is about 50201.8029656306. The cubic root of 2520221021 is about 1360.8582063462.

Adding to 2520221021 its reverse (1201220252), we get a palindrome (3721441273).

The spelling of 2520221021 in words is "two billion, five hundred twenty million, two hundred twenty-one thousand, twenty-one".