221397942 has 16 divisors (see below), whose sum is σ = 443151360. Its totient is φ = 73740072.

The previous prime is 221397923. The next prime is 221397947. The reversal of 221397942 is 249793122.

221397942 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221397942.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221397947) 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, 6342 + ... + 21977.

It is an arithmetic number, because the mean of its divisors is an integer number (27696960).

Almost surely, 2^221397942 is an apocalyptic number.

221397942 is an abundant number, since it is smaller than the sum of its proper divisors (221753418).

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

221397942 is a wasteful number, since it uses less digits than its factorization.

221397942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29627.

The product of its digits is 54432, while the sum is 39.

The square root of 221397942 is about 14879.4469655293. The cubic root of 221397942 is about 604.9570281160.

The spelling of 221397942 in words is "two hundred twenty-one million, three hundred ninety-seven thousand, nine hundred forty-two".