8987921 has 2 divisors, whose sum is σ = 8987922. Its totient is φ = 8987920.

The previous prime is 8987911. The next prime is 8987933. The reversal of 8987921 is 1297898.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7349521 + 1638400 = 2711^2 + 1280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8987921 is a prime.

It is not a weakly prime, because it can be changed into another prime (8987911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4493960 + 4493961.

It is an arithmetic number, because the mean of its divisors is an integer number (4493961).

Almost surely, 2^8987921 is an apocalyptic number.

It is an amenable number.

8987921 is a deficient number, since it is larger than the sum of its proper divisors (1).

8987921 is an equidigital number, since it uses as much as digits as its factorization.

8987921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 44.

The square root of 8987921 is about 2997.9861574063. The cubic root of 8987921 is about 207.9152838562.

The spelling of 8987921 in words is "eight million, nine hundred eighty-seven thousand, nine hundred twenty-one".