7681021 has 2 divisors, whose sum is σ = 7681022. Its totient is φ = 7681020.

The previous prime is 7681013. The next prime is 7681031. The reversal of 7681021 is 1201867.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3956121 + 3724900 = 1989^2 + 1930^2 .

It is a cyclic number.

It is not a de Polignac number, because 7681021 - 2³ = 7681013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7681031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3840510 + 3840511.

It is an arithmetic number, because the mean of its divisors is an integer number (3840511).

Almost surely, 2^7681021 is an apocalyptic number.

It is an amenable number.

7681021 is a deficient number, since it is larger than the sum of its proper divisors (1).

7681021 is an equidigital number, since it uses as much as digits as its factorization.

7681021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 7681021 is about 2771.4654968085. The cubic root of 7681021 is about 197.3057086234.

Adding to 7681021 its reverse (1201867), we get a palindrome (8882888).

The spelling of 7681021 in words is "seven million, six hundred eighty-one thousand, twenty-one".