221917420 has 24 divisors (see below), whose sum is σ = 477394848. Its totient is φ = 86601600.

The previous prime is 221917417. The next prime is 221917429. The reversal of 221917420 is 24719122.

221917420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (221917429) 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, 134496 + ... + 136135.

It is an arithmetic number, because the mean of its divisors is an integer number (19891452).

Almost surely, 2^221917420 is an apocalyptic number.

221917420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221917420 is an abundant number, since it is smaller than the sum of its proper divisors (255477428).

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

221917420 is a wasteful number, since it uses less digits than its factorization.

221917420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270681 (or 270679 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 221917420 is about 14896.8929646420. The cubic root of 221917420 is about 605.4298063696.

The spelling of 221917420 in words is "two hundred twenty-one million, nine hundred seventeen thousand, four hundred twenty".