221798738 has 16 divisors (see below), whose sum is σ = 392492544. Its totient is φ = 91990080.

The previous prime is 221798737. The next prime is 221798771. The reversal of 221798738 is 837897122.

It is a junction number, because it is equal to n+sod(n) for n = 221798692 and 221798701.

It is not an unprimeable number, because it can be changed into a prime (221798737) 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, 255095 + ... + 255962.

It is an arithmetic number, because the mean of its divisors is an integer number (24530784).

Almost surely, 2^221798738 is an apocalyptic number.

221798738 is a deficient number, since it is larger than the sum of its proper divisors (170693806).

221798738 is a wasteful number, since it uses less digits than its factorization.

221798738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511097.

The product of its digits is 338688, while the sum is 47.

The square root of 221798738 is about 14892.9089838084. The cubic root of 221798738 is about 605.3218586575.

The spelling of 221798738 in words is "two hundred twenty-one million, seven hundred ninety-eight thousand, seven hundred thirty-eight".