64005010021 has 4 divisors (see below), whose sum is σ = 64024958700. Its totient is φ = 63985061344.

The previous prime is 64005010009. The next prime is 64005010049. The reversal of 64005010021 is 12001050046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12001050046 = 2 ⋅6000525023.

It can be written as a sum of positive squares in 2 ways, for example, as 30891929121 + 33113080900 = 175761^2 + 181970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64005010021 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 (64005010001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9969526 + ... + 9975943.

It is an arithmetic number, because the mean of its divisors is an integer number (16006239675).

Almost surely, 2^64005010021 is an apocalyptic number.

It is an amenable number.

64005010021 is a deficient number, since it is larger than the sum of its proper divisors (19948679).

64005010021 is a wasteful number, since it uses less digits than its factorization.

64005010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19948678.

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 64005010021 its reverse (12001050046), we get a palindrome (76006060067).

The spelling of 64005010021 in words is "sixty-four billion, five million, ten thousand, twenty-one".