63437581 has 2 divisors, whose sum is σ = 63437582. Its totient is φ = 63437580.

The previous prime is 63437579. The next prime is 63437593. The reversal of 63437581 is 18573436.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61308900 + 2128681 = 7830^2 + 1459^2 .

It is a cyclic number.

It is not a de Polignac number, because 63437581 - 2¹ = 63437579 is a prime.

It is a super-2 number, since 2×63437581² = 8048653366263122, which contains 22 as substring.

Together with 63437579, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 63437581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63437551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31718790 + 31718791.

It is an arithmetic number, because the mean of its divisors is an integer number (31718791).

Almost surely, 2^63437581 is an apocalyptic number.

It is an amenable number.

63437581 is a deficient number, since it is larger than the sum of its proper divisors (1).

63437581 is an equidigital number, since it uses as much as digits as its factorization.

63437581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 37.

The square root of 63437581 is about 7964.7712459304. The cubic root of 63437581 is about 398.8248446558.

It can be divided in two parts, 6343 and 7581, that added together give a square (13924 = 118²).

The spelling of 63437581 in words is "sixty-three million, four hundred thirty-seven thousand, five hundred eighty-one".