221858364 has 288 divisors, whose sum is σ = 731691520. Its totient is φ = 50761728.

The previous prime is 221858363. The next prime is 221858389. The reversal of 221858364 is 463858122.

221858364 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221858364² = 98442267353512992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221858363) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5996154 + ... + 5996190.

Almost surely, 2^221858364 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 221858364, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (365845760).

221858364 is an abundant number, since it is smaller than the sum of its proper divisors (509833156).

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

221858364 is a wasteful number, since it uses less digits than its factorization.

221858364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117 (or 98 counting only the distinct ones).

The product of its digits is 92160, while the sum is 39.

The square root of 221858364 is about 14894.9106744552. The cubic root of 221858364 is about 605.3760965486.

It can be divided in two parts, 221858 and 364, that added together give a palindrome (222222).

The spelling of 221858364 in words is "two hundred twenty-one million, eight hundred fifty-eight thousand, three hundred sixty-four".