64884821 has 4 divisors (see below), whose sum is σ = 65192544. Its totient is φ = 64577100.

The previous prime is 64884797. The next prime is 64884823. The reversal of 64884821 is 12848846.

64884821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12848846 = 2 ⋅6424423.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64884821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64884823) 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 3 ways as a sum of consecutive naturals, for example, 153545 + ... + 153966.

It is an arithmetic number, because the mean of its divisors is an integer number (16298136).

Almost surely, 2^64884821 is an apocalyptic number.

It is an amenable number.

64884821 is a deficient number, since it is larger than the sum of its proper divisors (307723).

64884821 is a wasteful number, since it uses less digits than its factorization.

64884821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307722.

The product of its digits is 98304, while the sum is 41.

The square root of 64884821 is about 8055.1114827791. Note that the first 3 decimals coincide. The cubic root of 64884821 is about 401.8349466389.

The spelling of 64884821 in words is "sixty-four million, eight hundred eighty-four thousand, eight hundred twenty-one".