64739221 has 2 divisors, whose sum is σ = 64739222. Its totient is φ = 64739220.

The previous prime is 64739189. The next prime is 64739237. The reversal of 64739221 is 12293746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64160100 + 579121 = 8010^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 64739221 - 2⁵ = 64739189 is a prime.

It is equal to p_3826078 and since 64739221 and 3826078 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64739261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32369610 + 32369611.

It is an arithmetic number, because the mean of its divisors is an integer number (32369611).

Almost surely, 2^64739221 is an apocalyptic number.

It is an amenable number.

64739221 is a deficient number, since it is larger than the sum of its proper divisors (1).

64739221 is an equidigital number, since it uses as much as digits as its factorization.

64739221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 34.

The square root of 64739221 is about 8046.0686673679. The cubic root of 64739221 is about 401.5341521703.

The spelling of 64739221 in words is "sixty-four million, seven hundred thirty-nine thousand, two hundred twenty-one".