63521399 has 2 divisors, whose sum is σ = 63521400. Its totient is φ = 63521398.

The previous prime is 63521317. The next prime is 63521413. The reversal of 63521399 is 99312536.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 63521399 - 2¹² = 63517303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63521309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31760699 + 31760700.

It is an arithmetic number, because the mean of its divisors is an integer number (31760700).

Almost surely, 2^63521399 is an apocalyptic number.

63521399 is a deficient number, since it is larger than the sum of its proper divisors (1).

63521399 is an equidigital number, since it uses as much as digits as its factorization.

63521399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43740, while the sum is 38.

The square root of 63521399 is about 7970.0313048319. The cubic root of 63521399 is about 399.0004187574. Note that the first 3 decimals are identical.

The spelling of 63521399 in words is "sixty-three million, five hundred twenty-one thousand, three hundred ninety-nine".