8721929 has 2 divisors, whose sum is σ = 8721930. Its totient is φ = 8721928.

The previous prime is 8721917. The next prime is 8721941. The reversal of 8721929 is 9291278.

It is a balanced prime because it is at equal distance from previous prime (8721917) and next prime (8721941).

It can be written as a sum of positive squares in only one way, i.e., 4721929 + 4000000 = 2173^2 + 2000^2 .

It is a cyclic number.

It is not a de Polignac number, because 8721929 - 2⁴ = 8721913 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 8721892 and 8721901.

It is not a weakly prime, because it can be changed into another prime (8721989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360964 + 4360965.

It is an arithmetic number, because the mean of its divisors is an integer number (4360965).

Almost surely, 2^8721929 is an apocalyptic number.

It is an amenable number.

8721929 is a deficient number, since it is larger than the sum of its proper divisors (1).

8721929 is an equidigital number, since it uses as much as digits as its factorization.

8721929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 38.

The square root of 8721929 is about 2953.2912148991. The cubic root of 8721929 is about 205.8436696862.

The spelling of 8721929 in words is "eight million, seven hundred twenty-one thousand, nine hundred twenty-nine".