221631542 has 32 divisors (see below), whose sum is σ = 398373120. Its totient is φ = 91285920.

The previous prime is 221631539. The next prime is 221631551. The reversal of 221631542 is 245136122.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1913 + ... + 21140.

It is an arithmetic number, because the mean of its divisors is an integer number (12449160).

Almost surely, 2^221631542 is an apocalyptic number.

221631542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

221631542 is a deficient number, since it is larger than the sum of its proper divisors (176741578).

221631542 is a wasteful number, since it uses less digits than its factorization.

221631542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23108.

The product of its digits is 2880, while the sum is 26.

The square root of 221631542 is about 14887.2946501371. The cubic root of 221631542 is about 605.1697194769.

Adding to 221631542 its reverse (245136122), we get a palindrome (466767664).

The spelling of 221631542 in words is "two hundred twenty-one million, six hundred thirty-one thousand, five hundred forty-two".