8720621629 has 2 divisors, whose sum is σ = 8720621630. Its totient is φ = 8720621628.

The previous prime is 8720621621. The next prime is 8720621681. The reversal of 8720621629 is 9261260278.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7986103225 + 734518404 = 89365^2 + 27102^2 .

It is a cyclic number.

It is not a de Polignac number, because 8720621629 - 2³ = 8720621621 is a prime.

It is a super-2 number, since 2×8720621629² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8720621621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360310814 + 4360310815.

It is an arithmetic number, because the mean of its divisors is an integer number (4360310815).

Almost surely, 2^8720621629 is an apocalyptic number.

It is an amenable number.

8720621629 is a deficient number, since it is larger than the sum of its proper divisors (1).

8720621629 is an equidigital number, since it uses as much as digits as its factorization.

8720621629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 8720621629 is about 93384.2686377101. The cubic root of 8720621629 is about 2058.3338421339. Note that the first 3 decimals are identical.

The spelling of 8720621629 in words is "eight billion, seven hundred twenty million, six hundred twenty-one thousand, six hundred twenty-nine".