221320542 has 32 divisors (see below), whose sum is σ = 454726944. Its totient is φ = 71769600.

The previous prime is 221320523. The next prime is 221320543. The reversal of 221320542 is 245023122.

221320542 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 2×221320542² = 97965564622347528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221320543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102498 + ... + 104634.

It is an arithmetic number, because the mean of its divisors is an integer number (14210217).

Almost surely, 2^221320542 is an apocalyptic number.

221320542 is an abundant number, since it is smaller than the sum of its proper divisors (233406402).

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

221320542 is a wasteful number, since it uses less digits than its factorization.

221320542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2604.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 221320542 is about 14876.8458350552. The cubic root of 221320542 is about 604.8865228965.

Adding to 221320542 its reverse (245023122), we get a palindrome (466343664).

The spelling of 221320542 in words is "two hundred twenty-one million, three hundred twenty thousand, five hundred forty-two".