63615521 has 2 divisors, whose sum is σ = 63615522. Its totient is φ = 63615520.

The previous prime is 63615491. The next prime is 63615551. The reversal of 63615521 is 12551636.

It is a balanced prime because it is at equal distance from previous prime (63615491) and next prime (63615551).

It can be written as a sum of positive squares in only one way, i.e., 38254225 + 25361296 = 6185^2 + 5036^2 .

It is a cyclic number.

It is not a de Polignac number, because 63615521 - 2¹⁰ = 63614497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (63615551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31807760 + 31807761.

It is an arithmetic number, because the mean of its divisors is an integer number (31807761).

Almost surely, 2^63615521 is an apocalyptic number.

It is an amenable number.

63615521 is a deficient number, since it is larger than the sum of its proper divisors (1).

63615521 is an equidigital number, since it uses as much as digits as its factorization.

63615521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 29.

The square root of 63615521 is about 7975.9338638181. The cubic root of 63615521 is about 399.1973927143.

The spelling of 63615521 in words is "sixty-three million, six hundred fifteen thousand, five hundred twenty-one".