21221550055340 has 48 divisors (see below), whose sum is σ = 44582709334464. Its totient is φ = 8485296019200.

The previous prime is 21221550055289. The next prime is 21221550055361. The reversal of 21221550055340 is 4355005512212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221550055340.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1059954530 + ... + 1059974550.

It is an arithmetic number, because the mean of its divisors is an integer number (928806444468).

Almost surely, 2^{21221550055340} is an apocalyptic number.

21221550055340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221550055340 is an abundant number, since it is smaller than the sum of its proper divisors (23361159279124).

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

21221550055340 is a wasteful number, since it uses less digits than its factorization.

21221550055340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38138 (or 38136 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 35.

Adding to 21221550055340 its reverse (4355005512212), we get a palindrome (25576555567552).

The spelling of 21221550055340 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred fifty million, fifty-five thousand, three hundred forty".