64620257 has 16 divisors (see below), whose sum is σ = 71173200. Its totient is φ = 58309632.

The previous prime is 64620251. The next prime is 64620277. The reversal of 64620257 is 75202646.

64620257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 1957201 + 62663056 = 1399^2 + 7916^2 .

It is a cyclic number.

It is not a de Polignac number, because 64620257 - 2¹² = 64616161 is a prime.

It is a super-4 number, since 4×64620257⁴ (a number of 32 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64620251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141173 + ... + 141629.

It is an arithmetic number, because the mean of its divisors is an integer number (4448325).

Almost surely, 2^64620257 is an apocalyptic number.

It is an amenable number.

64620257 is a deficient number, since it is larger than the sum of its proper divisors (6552943).

64620257 is a wasteful number, since it uses less digits than its factorization.

64620257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 64620257 is about 8038.6725894267. The cubic root of 64620257 is about 401.2880499496.

The spelling of 64620257 in words is "sixty-four million, six hundred twenty thousand, two hundred fifty-seven".