8721481 has 2 divisors, whose sum is σ = 8721482. Its totient is φ = 8721480.

The previous prime is 8721473. The next prime is 8721487. The reversal of 8721481 is 1841278.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8173881 + 547600 = 2859^2 + 740^2 .

It is a cyclic number.

It is not a de Polignac number, because 8721481 - 2³ = 8721473 is a prime.

It is a super-2 number, since 2×8721481² = 152128461666722, which contains 22 as substring.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (8721487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360740 + 4360741.

It is an arithmetic number, because the mean of its divisors is an integer number (4360741).

Almost surely, 2^8721481 is an apocalyptic number.

It is an amenable number.

8721481 is a deficient number, since it is larger than the sum of its proper divisors (1).

8721481 is an equidigital number, since it uses as much as digits as its factorization.

8721481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3584, while the sum is 31.

The square root of 8721481 is about 2953.2153663423. The cubic root of 8721481 is about 205.8401452540.

The spelling of 8721481 in words is "eight million, seven hundred twenty-one thousand, four hundred eighty-one".