221770440 has 256 divisors, whose sum is σ = 802483200. Its totient is φ = 54263808.

The previous prime is 221770429. The next prime is 221770477. The reversal of 221770440 is 44077122.

It is a happy number.

221770440 is a `hidden beast` number, since 2 + 217 + 7 + 0 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 862792 + ... + 863048.

It is an arithmetic number, because the mean of its divisors is an integer number (3134700).

Almost surely, 2^221770440 is an apocalyptic number.

221770440 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 221770440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (401241600).

221770440 is an abundant number, since it is smaller than the sum of its proper divisors (580712760).

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

221770440 is a wasteful number, since it uses less digits than its factorization.

221770440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341 (or 331 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 221770440 is about 14891.9589040529. The cubic root of 221770440 is about 605.2961144075.

It can be divided in two parts, 221 and 770440, that added together give a triangular number (770661 = T₁₂₄₁).

The spelling of 221770440 in words is "two hundred twenty-one million, seven hundred seventy thousand, four hundred forty".