64005021 has 24 divisors (see below), whose sum is σ = 96947136. Its totient is φ = 40613760.

The previous prime is 64004989. The next prime is 64005031. The reversal of 64005021 is 12050046.

It is a happy number.

64005021 is a `hidden beast` number, since 640 + 0 + 5 + 0 + 21 = 666.

It is not a de Polignac number, because 64005021 - 2⁵ = 64004989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64004985 and 64005003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64005031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49246 + ... + 50528.

It is an arithmetic number, because the mean of its divisors is an integer number (4039464).

Almost surely, 2^64005021 is an apocalyptic number.

It is an amenable number.

64005021 is a deficient number, since it is larger than the sum of its proper divisors (32942115).

64005021 is a wasteful number, since it uses less digits than its factorization.

64005021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1553 (or 1550 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 64005021 is about 8000.3138063453. The cubic root of 64005021 is about 400.0104601431.

Adding to 64005021 its reverse (12050046), we get a palindrome (76055067).

The spelling of 64005021 in words is "sixty-four million, five thousand, twenty-one".