21355424544212 has 12 divisors (see below), whose sum is σ = 40769446857216. Its totient is φ = 9707011156440.

The previous prime is 21355424544101. The next prime is 21355424544281. The reversal of 21355424544212 is 21244542455312.

It is a Harshad number since it is a multiple of its sum of digits (44), and also a Moran number because the ratio is a prime number: 485350557823 = 21355424544212 / (2 + 1 + 3 + 5 + 5 + 4 + 2 + 4 + 5 + 4 + 4 + 2 + 1 + 2).

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, 242675278868 + ... + 242675278955.

It is an arithmetic number, because the mean of its divisors is an integer number (3397453904768).

Almost surely, 2^{21355424544212} is an apocalyptic number.

21355424544212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21355424544212 is a deficient number, since it is larger than the sum of its proper divisors (19414022313004).

21355424544212 is a wasteful number, since it uses less digits than its factorization.

21355424544212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485350557838 (or 485350557836 counting only the distinct ones).

The product of its digits is 1536000, while the sum is 44.

Adding to 21355424544212 its reverse (21244542455312), we get a palindrome (42599966999524).

The spelling of 21355424544212 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred twenty-four million, five hundred forty-four thousand, two hundred twelve".