64481531 has 4 divisors (see below), whose sum is σ = 65120064. Its totient is φ = 63843000.

The previous prime is 64481507. The next prime is 64481563. The reversal of 64481531 is 13518446.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64481531 is a prime.

It is a super-3 number, since 3×64481531³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64481831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 319115 + ... + 319316.

It is an arithmetic number, because the mean of its divisors is an integer number (16280016).

Almost surely, 2^64481531 is an apocalyptic number.

64481531 is a deficient number, since it is larger than the sum of its proper divisors (638533).

64481531 is a wasteful number, since it uses less digits than its factorization.

64481531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638532.

The product of its digits is 11520, while the sum is 32.

The square root of 64481531 is about 8030.0392900658. The cubic root of 64481531 is about 401.0006840742. Note that the first 3 decimals are identical.

Adding to 64481531 its reverse (13518446), we get a palindrome (77999977).

The spelling of 64481531 in words is "sixty-four million, four hundred eighty-one thousand, five hundred thirty-one".