2571021 has 10 divisors (see below), whose sum is σ = 3840782. Its totient is φ = 1713960.

The previous prime is 2571017. The next prime is 2571031. The reversal of 2571021 is 1201752.

It can be written as a sum of positive squares in only one way, i.e., 2368521 + 202500 = 1539^2 + 450^2 .

It is not a de Polignac number, because 2571021 - 2² = 2571017 is a prime.

It is a super-2 number, since 2×2571021² = 13220297964882, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

2571021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2570985 and 2571003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2571001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 15790 + ... + 15951.

2^2571021 is an apocalyptic number.

It is an amenable number.

2571021 is a deficient number, since it is larger than the sum of its proper divisors (1269761).

2571021 is an equidigital number, since it uses as much as digits as its factorization.

2571021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31753 (or 31744 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 2571021 is about 1603.4403637180. The cubic root of 2571021 is about 136.9941034989.

Adding to 2571021 its reverse (1201752), we get a palindrome (3772773).

The spelling of 2571021 in words is "two million, five hundred seventy-one thousand, twenty-one".