63431581 has 2 divisors, whose sum is σ = 63431582. Its totient is φ = 63431580.

The previous prime is 63431561. The next prime is 63431587. The reversal of 63431581 is 18513436.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63059481 + 372100 = 7941^2 + 610^2 .

It is a cyclic number.

It is not a de Polignac number, because 63431581 - 2¹³ = 63423389 is a prime.

It is a super-2 number, since 2×63431581² = 8047130936319122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63431587) 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, 31715790 + 31715791.

It is an arithmetic number, because the mean of its divisors is an integer number (31715791).

Almost surely, 2^63431581 is an apocalyptic number.

It is an amenable number.

63431581 is a deficient number, since it is larger than the sum of its proper divisors (1).

63431581 is an equidigital number, since it uses as much as digits as its factorization.

63431581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 31.

The square root of 63431581 is about 7964.3945783719. The cubic root of 63431581 is about 398.8122704872.

The spelling of 63431581 in words is "sixty-three million, four hundred thirty-one thousand, five hundred eighty-one".