64220521 has 2 divisors, whose sum is σ = 64220522. Its totient is φ = 64220520.

The previous prime is 64220489. The next prime is 64220539. The reversal of 64220521 is 12502246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61544025 + 2676496 = 7845^2 + 1636^2 .

It is a cyclic number.

It is not a de Polignac number, because 64220521 - 2⁵ = 64220489 is a prime.

It is a super-2 number, since 2×64220521² = 8248550635022882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 64220492 and 64220501.

It is not a weakly prime, because it can be changed into another prime (64220581) 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, 32110260 + 32110261.

It is an arithmetic number, because the mean of its divisors is an integer number (32110261).

Almost surely, 2^64220521 is an apocalyptic number.

It is an amenable number.

64220521 is a deficient number, since it is larger than the sum of its proper divisors (1).

64220521 is an equidigital number, since it uses as much as digits as its factorization.

64220521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 64220521 is about 8013.7707104708. The cubic root of 64220521 is about 400.4588920938.

Adding to 64220521 its reverse (12502246), we get a palindrome (76722767).

The spelling of 64220521 in words is "sixty-four million, two hundred twenty thousand, five hundred twenty-one".