221772640 has 24 divisors (see below), whose sum is σ = 523938240. Its totient is φ = 88708992.

The previous prime is 221772631. The next prime is 221772659. The reversal of 221772640 is 46277122.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 692880 + ... + 693199.

It is an arithmetic number, because the mean of its divisors is an integer number (21830760).

Almost surely, 2^221772640 is an apocalyptic number.

221772640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221772640 is an abundant number, since it is smaller than the sum of its proper divisors (302165600).

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

221772640 is a wasteful number, since it uses less digits than its factorization.

221772640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386094 (or 1386086 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 221772640 is about 14892.0327692360. The cubic root of 221772640 is about 605.2981159473.

The spelling of 221772640 in words is "two hundred twenty-one million, seven hundred seventy-two thousand, six hundred forty".