64733821 has 2 divisors, whose sum is σ = 64733822. Its totient is φ = 64733820.

The previous prime is 64733813. The next prime is 64733833. The reversal of 64733821 is 12833746.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61544025 + 3189796 = 7845^2 + 1786^2 .

It is a cyclic number.

It is not a de Polignac number, because 64733821 - 2³ = 64733813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64733321) 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 as a sum of consecutive naturals, namely, 32366910 + 32366911.

It is an arithmetic number, because the mean of its divisors is an integer number (32366911).

Almost surely, 2^64733821 is an apocalyptic number.

It is an amenable number.

64733821 is a deficient number, since it is larger than the sum of its proper divisors (1).

64733821 is an equidigital number, since it uses as much as digits as its factorization.

64733821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 34.

The square root of 64733821 is about 8045.7330927641. The cubic root of 64733821 is about 401.5229876620.

The spelling of 64733821 in words is "sixty-four million, seven hundred thirty-three thousand, eight hundred twenty-one".