221996628 has 36 divisors (see below), whose sum is σ = 641324320. Its totient is φ = 63427536.

The previous prime is 221996609. The next prime is 221996641. The reversal of 221996628 is 826699122.

221996628 is a `hidden beast` number, since 2 + 2 + 19 + 9 + 6 + 628 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 440218 + ... + 440721.

Almost surely, 2^221996628 is an apocalyptic number.

221996628 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

221996628 is an abundant number, since it is smaller than the sum of its proper divisors (419327692).

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

221996628 is a wasteful number, since it uses less digits than its factorization.

221996628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880956 (or 880951 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 221996628 is about 14899.5512684107. The cubic root of 221996628 is about 605.5018289261.

The spelling of 221996628 in words is "two hundred twenty-one million, nine hundred ninety-six thousand, six hundred twenty-eight".