63725621 has 2 divisors, whose sum is σ = 63725622. Its totient is φ = 63725620.

The previous prime is 63725609. The next prime is 63725633. The reversal of 63725621 is 12652736.

It is a balanced prime because it is at equal distance from previous prime (63725609) and next prime (63725633).

It can be written as a sum of positive squares in only one way, i.e., 63377521 + 348100 = 7961^2 + 590^2 .

It is a cyclic number.

It is not a de Polignac number, because 63725621 - 2¹⁰ = 63724597 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63725021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31862810 + 31862811.

It is an arithmetic number, because the mean of its divisors is an integer number (31862811).

Almost surely, 2^63725621 is an apocalyptic number.

It is an amenable number.

63725621 is a deficient number, since it is larger than the sum of its proper divisors (1).

63725621 is an equidigital number, since it uses as much as digits as its factorization.

63725621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 32.

The square root of 63725621 is about 7982.8328931527. The cubic root of 63725621 is about 399.4275582502.

It can be divided in two parts, 63725 and 621, that added together give a palindrome (64346).

The spelling of 63725621 in words is "sixty-three million, seven hundred twenty-five thousand, six hundred twenty-one".