221551040 has 28 divisors (see below), whose sum is σ = 527569176. Its totient is φ = 88620288.

The previous prime is 221551009. The next prime is 221551061. The reversal of 221551040 is 40155122.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 345854 + ... + 346493.

Almost surely, 2^221551040 is an apocalyptic number.

221551040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221551040 is an abundant number, since it is smaller than the sum of its proper divisors (306018136).

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

221551040 is an equidigital number, since it uses as much as digits as its factorization.

221551040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692364 (or 692354 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 221551040 is about 14884.5906897032. The cubic root of 221551040 is about 605.0964397864.

The spelling of 221551040 in words is "two hundred twenty-one million, five hundred fifty-one thousand, forty".