9487636721 has 2 divisors, whose sum is σ = 9487636722. Its totient is φ = 9487636720.

The previous prime is 9487636687. The next prime is 9487636729. The reversal of 9487636721 is 1276367849.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6288490000 + 3199146721 = 79300^2 + 56561^2 .

It is a cyclic number.

It is not a de Polignac number, because 9487636721 - 2¹⁰ = 9487635697 is a prime.

It is not a weakly prime, because it can be changed into another prime (9487636729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4743818360 + 4743818361.

It is an arithmetic number, because the mean of its divisors is an integer number (4743818361).

Almost surely, 2^9487636721 is an apocalyptic number.

It is an amenable number.

9487636721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9487636721 is an equidigital number, since it uses as much as digits as its factorization.

9487636721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 53.

The square root of 9487636721 is about 97404.5005171732. The cubic root of 9487636721 is about 2116.9926447117.

The spelling of 9487636721 in words is "nine billion, four hundred eighty-seven million, six hundred thirty-six thousand, seven hundred twenty-one".