63436721 has 2 divisors, whose sum is σ = 63436722. Its totient is φ = 63436720.

The previous prime is 63436697. The next prime is 63436727. The reversal of 63436721 is 12763436.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59845696 + 3591025 = 7736^2 + 1895^2 .

It is a cyclic number.

It is not a de Polignac number, because 63436721 - 2⁶ = 63436657 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (63436727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31718360 + 31718361.

It is an arithmetic number, because the mean of its divisors is an integer number (31718361).

Almost surely, 2^63436721 is an apocalyptic number.

It is an amenable number.

63436721 is a deficient number, since it is larger than the sum of its proper divisors (1).

63436721 is an equidigital number, since it uses as much as digits as its factorization.

63436721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 32.

The square root of 63436721 is about 7964.7172580073. The cubic root of 63436721 is about 398.8230424070.

The spelling of 63436721 in words is "sixty-three million, four hundred thirty-six thousand, seven hundred twenty-one".