2251021 has 6 divisors (see below), whose sum is σ = 2391530. Its totient is φ = 2118336.

The previous prime is 2251001. The next prime is 2251031. The reversal of 2251021 is 1201522.

It can be written as a sum of positive squares in 3 ways, for example, as 1010025 + 1240996 = 1005^2 + 1114^2 .

It is not a de Polignac number, because 2251021 - 2⁹ = 2250509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2250992 and 2251010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2251001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3606 + ... + 4183.

2^2251021 is an apocalyptic number.

It is an amenable number.

2251021 is a deficient number, since it is larger than the sum of its proper divisors (140509).

2251021 is an equidigital number, since it uses as much as digits as its factorization.

2251021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7823 (or 7806 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 2251021 is about 1500.3402947332. The cubic root of 2251021 is about 131.0568872833.

Adding to 2251021 its reverse (1201522), we get a palindrome (3452543).

The spelling of 2251021 in words is "two million, two hundred fifty-one thousand, twenty-one".