221423240 has 32 divisors (see below), whose sum is σ = 498960000. Its totient is φ = 88434624.

The previous prime is 221423203. The next prime is 221423243. The reversal of 221423240 is 42324122.

It is a super-3 number, since 3×221423240³ (a number of 26 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (221423243) 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, 24911 + ... + 32609.

It is an arithmetic number, because the mean of its divisors is an integer number (15592500).

Almost surely, 2^221423240 is an apocalyptic number.

221423240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221423240 is an abundant number, since it is smaller than the sum of its proper divisors (277536760).

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

221423240 is a wasteful number, since it uses less digits than its factorization.

221423240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8429 (or 8425 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 221423240 is about 14880.2970400459. The cubic root of 221423240 is about 604.9800690108.

Adding to 221423240 its reverse (42324122), we get a palindrome (263747362).

The spelling of 221423240 in words is "two hundred twenty-one million, four hundred twenty-three thousand, two hundred forty".