8891621 has 2 divisors, whose sum is σ = 8891622. Its totient is φ = 8891620.

The previous prime is 8891611. The next prime is 8891627. The reversal of 8891621 is 1261988.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7214596 + 1677025 = 2686^2 + 1295^2 .

It is a cyclic number.

It is not a de Polignac number, because 8891621 - 2⁶ = 8891557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8891627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4445810 + 4445811.

It is an arithmetic number, because the mean of its divisors is an integer number (4445811).

Almost surely, 2^8891621 is an apocalyptic number.

It is an amenable number.

8891621 is a deficient number, since it is larger than the sum of its proper divisors (1).

8891621 is an equidigital number, since it uses as much as digits as its factorization.

8891621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 35.

The square root of 8891621 is about 2981.8821237601. The cubic root of 8891621 is about 207.1700548174.

The spelling of 8891621 in words is "eight million, eight hundred ninety-one thousand, six hundred twenty-one".