221215064 has 32 divisors (see below), whose sum is σ = 478394400. Its totient is φ = 93934080.

The previous prime is 221215061. The next prime is 221215069. The reversal of 221215064 is 460512122.

It is a happy number.

It is a super-2 number, since 2×221215064² = 97872209081048192, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221215061) 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, 12017 + ... + 24224.

It is an arithmetic number, because the mean of its divisors is an integer number (14949825).

Almost surely, 2^221215064 is an apocalyptic number.

It is an amenable number.

221215064 is an abundant number, since it is smaller than the sum of its proper divisors (257179336).

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

221215064 is a wasteful number, since it uses less digits than its factorization.

221215064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36363 (or 36359 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 221215064 is about 14873.3003734881. The cubic root of 221215064 is about 604.7904143918.

Adding to 221215064 its reverse (460512122), we get a palindrome (681727186).

The spelling of 221215064 in words is "two hundred twenty-one million, two hundred fifteen thousand, sixty-four".