8007921 has 6 divisors (see below), whose sum is σ = 11567010. Its totient is φ = 5338608.

The previous prime is 8007917. The next prime is 8007931. The reversal of 8007921 is 1297008.

It can be written as a sum of positive squares in only one way, i.e., 5574321 + 2433600 = 2361^2 + 1560^2 .

It is not a de Polignac number, because 8007921 - 2² = 8007917 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (8007931) 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, 444876 + ... + 444893.

It is an arithmetic number, because the mean of its divisors is an integer number (1927835).

Almost surely, 2^8007921 is an apocalyptic number.

It is an amenable number.

8007921 is a deficient number, since it is larger than the sum of its proper divisors (3559089).

8007921 is a wasteful number, since it uses less digits than its factorization.

8007921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889775 (or 889772 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 8007921 is about 2829.8270265159. The cubic root of 8007921 is about 200.0659865598.

The spelling of 8007921 in words is "eight million, seven thousand, nine hundred twenty-one".