7988021 has 4 divisors (see below), whose sum is σ = 8263500. Its totient is φ = 7712544.

The previous prime is 7988009. The next prime is 7988033. The reversal of 7988021 is 1208897.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1208897 = 911 ⋅1327.

It is an interprime number because it is at equal distance from previous prime (7988009) and next prime (7988033).

It can be written as a sum of positive squares in 2 ways, for example, as 4431025 + 3556996 = 2105^2 + 1886^2 .

It is a cyclic number.

It is not a de Polignac number, because 7988021 - 2⁶ = 7987957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7988081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137696 + ... + 137753.

It is an arithmetic number, because the mean of its divisors is an integer number (2065875).

Almost surely, 2^7988021 is an apocalyptic number.

It is an amenable number.

7988021 is a deficient number, since it is larger than the sum of its proper divisors (275479).

7988021 is a wasteful number, since it uses less digits than its factorization.

7988021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275478.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 7988021 is about 2826.3087234058. The cubic root of 7988021 is about 199.9001251334.

The spelling of 7988021 in words is "seven million, nine hundred eighty-eight thousand, twenty-one".