5638698521 has 2 divisors, whose sum is σ = 5638698522. Its totient is φ = 5638698520.

The previous prime is 5638698497. The next prime is 5638698529. The reversal of 5638698521 is 1258968365.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5555615296 + 83083225 = 74536^2 + 9115^2 .

It is a cyclic number.

It is not a de Polignac number, because 5638698521 - 2²² = 5634504217 is a prime.

It is not a weakly prime, because it can be changed into another prime (5638698529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2819349260 + 2819349261.

It is an arithmetic number, because the mean of its divisors is an integer number (2819349261).

Almost surely, 2^5638698521 is an apocalyptic number.

It is an amenable number.

5638698521 is a deficient number, since it is larger than the sum of its proper divisors (1).

5638698521 is an equidigital number, since it uses as much as digits as its factorization.

5638698521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3110400, while the sum is 53.

The square root of 5638698521 is about 75091.2679410862. The cubic root of 5638698521 is about 1779.8891612379.

The spelling of 5638698521 in words is "five billion, six hundred thirty-eight million, six hundred ninety-eight thousand, five hundred twenty-one".