8721541 has 2 divisors, whose sum is σ = 8721542. Its totient is φ = 8721540.

The previous prime is 8721539. The next prime is 8721599. The reversal of 8721541 is 1451278.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6630625 + 2090916 = 2575^2 + 1446^2 .

It is a cyclic number.

It is not a de Polignac number, because 8721541 - 2¹ = 8721539 is a prime.

Together with 8721539, it forms a pair of twin primes.

It is a Chen prime.

8721541 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8721511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360770 + 4360771.

It is an arithmetic number, because the mean of its divisors is an integer number (4360771).

Almost surely, 2^8721541 is an apocalyptic number.

It is an amenable number.

8721541 is a deficient number, since it is larger than the sum of its proper divisors (1).

8721541 is an equidigital number, since it uses as much as digits as its factorization.

8721541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2240, while the sum is 28.

The square root of 8721541 is about 2953.2255247441. The cubic root of 8721541 is about 205.8406172832.

The spelling of 8721541 in words is "eight million, seven hundred twenty-one thousand, five hundred forty-one".