221210031440 has 20 divisors (see below), whose sum is σ = 514313323284. Its totient is φ = 88484012544.

The previous prime is 221210031439. The next prime is 221210031457. The reversal of 221210031440 is 44130012122.

It can be written as a sum of positive squares in 2 ways, for example, as 69103791376 + 152106240064 = 262876^2 + 390008^2 .

It is a tau number, because it is divible by the number of its divisors (20).

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, 1382562617 + ... + 1382562776.

Almost surely, 2^221210031440 is an apocalyptic number.

221210031440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221210031440 is an abundant number, since it is smaller than the sum of its proper divisors (293103291844).

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

221210031440 is a wasteful number, since it uses less digits than its factorization.

221210031440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2765125406 (or 2765125400 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 221210031440 its reverse (44130012122), we get a palindrome (265340043562).

The spelling of 221210031440 in words is "two hundred twenty-one billion, two hundred ten million, thirty-one thousand, four hundred forty".