221877428 has 6 divisors (see below), whose sum is σ = 388285506. Its totient is φ = 110938712.

The previous prime is 221877367. The next prime is 221877443. The reversal of 221877428 is 824778122.

221877428 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 135536164 + 86341264 = 11642^2 + 9292^2 .

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, 27734675 + ... + 27734682.

It is an arithmetic number, because the mean of its divisors is an integer number (64714251).

Almost surely, 2^221877428 is an apocalyptic number.

It is an amenable number.

221877428 is a deficient number, since it is larger than the sum of its proper divisors (166408078).

221877428 is a wasteful number, since it uses less digits than its factorization.

221877428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55469361 (or 55469359 counting only the distinct ones).

The product of its digits is 100352, while the sum is 41.

The square root of 221877428 is about 14895.5506108368. The cubic root of 221877428 is about 605.3934357782.

The spelling of 221877428 in words is "two hundred twenty-one million, eight hundred seventy-seven thousand, four hundred twenty-eight".