64056821 has 4 divisors (see below), whose sum is σ = 64074144. Its totient is φ = 64039500.

The previous prime is 64056803. The next prime is 64056829. The reversal of 64056821 is 12865046.

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.

It is a cyclic number.

It is not a de Polignac number, because 64056821 - 2¹⁸ = 63794677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64056829) 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 in 3 ways as a sum of consecutive naturals, for example, 635 + ... + 11336.

It is an arithmetic number, because the mean of its divisors is an integer number (16018536).

Almost surely, 2^64056821 is an apocalyptic number.

It is an amenable number.

64056821 is a deficient number, since it is larger than the sum of its proper divisors (17323).

64056821 is a wasteful number, since it uses less digits than its factorization.

64056821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17322.

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

The square root of 64056821 is about 8003.5505246109. The cubic root of 64056821 is about 400.1183420678.

The spelling of 64056821 in words is "sixty-four million, fifty-six thousand, eight hundred twenty-one".