63721543 has 2 divisors, whose sum is σ = 63721544. Its totient is φ = 63721542.

The previous prime is 63721517. The next prime is 63721561. The reversal of 63721543 is 34512736.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63721543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63721513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31860771 + 31860772.

It is an arithmetic number, because the mean of its divisors is an integer number (31860772).

Almost surely, 2^63721543 is an apocalyptic number.

63721543 is a deficient number, since it is larger than the sum of its proper divisors (1).

63721543 is an equidigital number, since it uses as much as digits as its factorization.

63721543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 31.

The square root of 63721543 is about 7982.5774659567. The cubic root of 63721543 is about 399.4190378660.

The spelling of 63721543 in words is "sixty-three million, seven hundred twenty-one thousand, five hundred forty-three".