2500021 has 4 divisors (see below), whose sum is σ = 2503872. Its totient is φ = 2496172.

The previous prime is 2500009. The next prime is 2500027. The reversal of 2500021 is 1200052.

2500021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is the 646-th star number.

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 2500021 - 2⁵ = 2499989 is a prime.

It is a Duffinian number.

2500021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2499980 and 2500007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2500027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 685 + ... + 2338.

It is an arithmetic number, because the mean of its divisors is an integer number (625968).

2^2500021 is an apocalyptic number.

It is an amenable number.

2500021 is a deficient number, since it is larger than the sum of its proper divisors (3851).

2500021 is an equidigital number, since it uses as much as digits as its factorization.

2500021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3850.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 2500021 is about 1581.1454708533. The cubic root of 2500021 is about 135.7212608471.

Adding to 2500021 its reverse (1200052), we get a palindrome (3700073).

The spelling of 2500021 in words is "two million, five hundred thousand, twenty-one".