221421651550 has 24 divisors (see below), whose sum is σ = 449284661352. Its totient is φ = 80516964000.

The previous prime is 221421651509. The next prime is 221421651569. The reversal of 221421651550 is 55156124122.

221421651550 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 201291861 + ... + 201292960.

It is an arithmetic number, because the mean of its divisors is an integer number (18720194223).

Almost surely, 2^221421651550 is an apocalyptic number.

221421651550 is an abundant number, since it is smaller than the sum of its proper divisors (227863009802).

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

221421651550 is a wasteful number, since it uses less digits than its factorization.

221421651550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402584844 (or 402584839 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 34.

Adding to 221421651550 its reverse (55156124122), we get a palindrome (276577775672).

The spelling of 221421651550 in words is "two hundred twenty-one billion, four hundred twenty-one million, six hundred fifty-one thousand, five hundred fifty".