63612721 has 2 divisors, whose sum is σ = 63612722. Its totient is φ = 63612720.

The previous prime is 63612709. The next prime is 63612743. The reversal of 63612721 is 12721636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44076321 + 19536400 = 6639^2 + 4420^2 .

It is a cyclic number.

It is not a de Polignac number, because 63612721 - 2¹⁵ = 63579953 is a prime.

It is a Chen prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 63612721.

It is not a weakly prime, because it can be changed into another prime (63612701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31806360 + 31806361.

It is an arithmetic number, because the mean of its divisors is an integer number (31806361).

Almost surely, 2^63612721 is an apocalyptic number.

It is an amenable number.

63612721 is a deficient number, since it is larger than the sum of its proper divisors (1).

63612721 is an equidigital number, since it uses as much as digits as its factorization.

63612721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 28.

The square root of 63612721 is about 7975.7583338514. The cubic root of 63612721 is about 399.1915358150.

The spelling of 63612721 in words is "sixty-three million, six hundred twelve thousand, seven hundred twenty-one".