64221580 has 72 divisors (see below), whose sum is σ = 147301056. Its totient is φ = 23500800.

The previous prime is 64221541. The next prime is 64221583. The reversal of 64221580 is 8512246.

It is a super-2 number, since 2×64221580² = 8248822675392800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64221583) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 236845 + ... + 237115.

It is an arithmetic number, because the mean of its divisors is an integer number (2045848).

Almost surely, 2^64221580 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64221580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73650528).

64221580 is an abundant number, since it is smaller than the sum of its proper divisors (83079476).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64221580 is a wasteful number, since it uses less digits than its factorization.

64221580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 64221580 is about 8013.8367839631. The cubic root of 64221580 is about 400.4610932782.

It can be divided in two parts, 642 and 21580, that added together give a palindrome (22222).

The spelling of 64221580 in words is "sixty-four million, two hundred twenty-one thousand, five hundred eighty".