221280878 has 64 divisors (see below), whose sum is σ = 435456000. Its totient is φ = 81886464.

The previous prime is 221280811. The next prime is 221280887. The reversal of 221280878 is 878082122.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 307403 + ... + 308121.

It is an arithmetic number, because the mean of its divisors is an integer number (6804000).

Almost surely, 2^221280878 is an apocalyptic number.

221280878 is a deficient number, since it is larger than the sum of its proper divisors (214175122).

221280878 is a wasteful number, since it uses less digits than its factorization.

221280878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849.

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 221280878 is about 14875.5126970468. The cubic root of 221280878 is about 604.8503857894.

The spelling of 221280878 in words is "two hundred twenty-one million, two hundred eighty thousand, eight hundred seventy-eight".