221739764 has 6 divisors (see below), whose sum is σ = 388044594. Its totient is φ = 110869880.

The previous prime is 221739701. The next prime is 221739811. The reversal of 221739764 is 467937122.

It can be written as a sum of positive squares in only one way, i.e., 156000100 + 65739664 = 12490^2 + 8108^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27717467 + ... + 27717474.

It is an arithmetic number, because the mean of its divisors is an integer number (64674099).

Almost surely, 2^221739764 is an apocalyptic number.

It is an amenable number.

221739764 is a deficient number, since it is larger than the sum of its proper divisors (166304830).

221739764 is a wasteful number, since it uses less digits than its factorization.

221739764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55434945 (or 55434943 counting only the distinct ones).

The product of its digits is 127008, while the sum is 41.

The square root of 221739764 is about 14890.9289166257. The cubic root of 221739764 is about 605.2682042860.

The spelling of 221739764 in words is "two hundred twenty-one million, seven hundred thirty-nine thousand, seven hundred sixty-four".