221151840 has 384 divisors, whose sum is σ = 881943552. Its totient is φ = 45342720.

The previous prime is 221151823. The next prime is 221151863. The reversal of 221151840 is 48151122.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 221151840.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2664439 + ... + 2664521.

It is an arithmetic number, because the mean of its divisors is an integer number (2296728).

Almost surely, 2^221151840 is an apocalyptic number.

221151840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221151840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (440971776).

221151840 is an abundant number, since it is smaller than the sum of its proper divisors (660791712).

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

221151840 is a wasteful number, since it uses less digits than its factorization.

221151840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 221151840 is about 14871.1748022811. The cubic root of 221151840 is about 604.7327918655.

The spelling of 221151840 in words is "two hundred twenty-one million, one hundred fifty-one thousand, eight hundred forty".