64218557 has 8 divisors (see below), whose sum is σ = 71543640. Its totient is φ = 57234240.

The previous prime is 64218541. The next prime is 64218589. The reversal of 64218557 is 75581246.

It can be written as a sum of positive squares in 4 ways, for example, as 42436 + 64176121 = 206^2 + 8011^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64218557 - 2⁴ = 64218541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64218557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64218857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84794 + ... + 85547.

It is an arithmetic number, because the mean of its divisors is an integer number (8942955).

Almost surely, 2^64218557 is an apocalyptic number.

It is an amenable number.

64218557 is a deficient number, since it is larger than the sum of its proper divisors (7325083).

64218557 is a wasteful number, since it uses less digits than its factorization.

64218557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170383.

The product of its digits is 67200, while the sum is 38.

The square root of 64218557 is about 8013.6481704652. The cubic root of 64218557 is about 400.4548097575.

The spelling of 64218557 in words is "sixty-four million, two hundred eighteen thousand, five hundred fifty-seven".