64506981 has 64 divisors (see below), whose sum is σ = 112896000. Its totient is φ = 32457600.

The previous prime is 64506971. The next prime is 64507013. The reversal of 64506981 is 18960546.

64506981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 64506981 - 2⁶ = 64506917 is a prime.

It is a super-2 number, since 2×64506981² = 8322301195468722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64506931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 464010 + ... + 464148.

It is an arithmetic number, because the mean of its divisors is an integer number (1764000).

Almost surely, 2^64506981 is an apocalyptic number.

It is an amenable number.

64506981 is a deficient number, since it is larger than the sum of its proper divisors (48389019).

64506981 is a wasteful number, since it uses less digits than its factorization.

64506981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 64506981 is about 8031.6238084213. The cubic root of 64506981 is about 401.0534336749.

It can be divided in two parts, 6450 and 6981, that added together give a palindrome (13431).

The spelling of 64506981 in words is "sixty-four million, five hundred six thousand, nine hundred eighty-one".