64066821 has 32 divisors (see below), whose sum is σ = 106149120. Its totient is φ = 33467904.

The previous prime is 64066813. The next prime is 64066837. The reversal of 64066821 is 12866046.

It is a happy number.

It is not a de Polignac number, because 64066821 - 2³ = 64066813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64066811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28681 + ... + 30833.

It is an arithmetic number, because the mean of its divisors is an integer number (3317160).

Almost surely, 2^64066821 is an apocalyptic number.

It is an amenable number.

64066821 is a deficient number, since it is larger than the sum of its proper divisors (42082299).

64066821 is a wasteful number, since it uses less digits than its factorization.

64066821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2285.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 64066821 is about 8004.1752229696. The cubic root of 64066821 is about 400.1391619959.

The spelling of 64066821 in words is "sixty-four million, sixty-six thousand, eight hundred twenty-one".