2021257 has 4 divisors (see below), whose sum is σ = 2310016. Its totient is φ = 1732500.

The previous prime is 2021251. The next prime is 2021291. The reversal of 2021257 is 7521202.

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 de Polignac number, because none of the positive numbers 2^k-2021257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144369 + ... + 144382.

It is an arithmetic number, because the mean of its divisors is an integer number (577504).

2^2021257 is an apocalyptic number.

It is an amenable number.

2021257 is a deficient number, since it is larger than the sum of its proper divisors (288759).

2021257 is an equidigital number, since it uses as much as digits as its factorization.

2021257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288758.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 2021257 is about 1421.7091826390. The cubic root of 2021257 is about 126.4369018798.

Adding to 2021257 its reverse (7521202), we get a palindrome (9542459).

Subtracting 2021257 from its reverse (7521202), we obtain a palindrome (5499945).

It can be divided in two parts, 2021 and 257, that added together give a triangular number (2278 = T₆₇).

The spelling of 2021257 in words is "two million, twenty-one thousand, two hundred fifty-seven".