221635420 has 12 divisors (see below), whose sum is σ = 465434424. Its totient is φ = 88654160.

The previous prime is 221635417. The next prime is 221635451. The reversal of 221635420 is 24536122.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5540866 + ... + 5540905.

It is an arithmetic number, because the mean of its divisors is an integer number (38786202).

Almost surely, 2^221635420 is an apocalyptic number.

221635420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221635420 is an abundant number, since it is smaller than the sum of its proper divisors (243799004).

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

221635420 is a wasteful number, since it uses less digits than its factorization.

221635420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11081780 (or 11081778 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 221635420 is about 14887.4248948567. The cubic root of 221635420 is about 605.1732491106.

It can be divided in two parts, 2216 and 35420, that added together give a square (37636 = 194²).

The spelling of 221635420 in words is "two hundred twenty-one million, six hundred thirty-five thousand, four hundred twenty".