63969521 has 16 divisors (see below), whose sum is σ = 84447360. Its totient is φ = 46913280.

The previous prime is 63969481. The next prime is 63969533. The reversal of 63969521 is 12596936.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63969521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63969571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23126 + ... + 25743.

It is an arithmetic number, because the mean of its divisors is an integer number (5277960).

Almost surely, 2^63969521 is an apocalyptic number.

It is an amenable number.

63969521 is a deficient number, since it is larger than the sum of its proper divisors (20477839).

63969521 is a wasteful number, since it uses less digits than its factorization.

63969521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48904.

The product of its digits is 87480, while the sum is 41.

The square root of 63969521 is about 7998.0948356468. The cubic root of 63969521 is about 399.9364920007.

The spelling of 63969521 in words is "sixty-three million, nine hundred sixty-nine thousand, five hundred twenty-one".