8749421 has 2 divisors, whose sum is σ = 8749422. Its totient is φ = 8749420.

The previous prime is 8749417. The next prime is 8749423. The reversal of 8749421 is 1249478.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6817321 + 1932100 = 2611^2 + 1390^2 .

It is a cyclic number.

It is not a de Polignac number, because 8749421 - 2² = 8749417 is a prime.

Together with 8749423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8749423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4374710 + 4374711.

It is an arithmetic number, because the mean of its divisors is an integer number (4374711).

Almost surely, 2^8749421 is an apocalyptic number.

It is an amenable number.

8749421 is a deficient number, since it is larger than the sum of its proper divisors (1).

8749421 is an equidigital number, since it uses as much as digits as its factorization.

8749421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 35.

The square root of 8749421 is about 2957.9420210680. The cubic root of 8749421 is about 206.0597197012.

The spelling of 8749421 in words is "eight million, seven hundred forty-nine thousand, four hundred twenty-one".