21506211101230 has 32 divisors (see below), whose sum is σ = 38923774797600. Its totient is φ = 8555365969920.

The previous prime is 21506211101201. The next prime is 21506211101261. The reversal of 21506211101230 is 3210111260512.

It is a junction number, because it is equal to n+sod(n) for n = 21506211101195 and 21506211101204.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6422551 + ... + 9179410.

It is an arithmetic number, because the mean of its divisors is an integer number (1216367962425).

Almost surely, 2^{21506211101230} is an apocalyptic number.

21506211101230 is a deficient number, since it is larger than the sum of its proper divisors (17417563696370).

21506211101230 is a wasteful number, since it uses less digits than its factorization.

21506211101230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15602724.

The product of its (nonzero) digits is 720, while the sum is 25.

Adding to 21506211101230 its reverse (3210111260512), we get a palindrome (24716322361742).

The spelling of 21506211101230 in words is "twenty-one trillion, five hundred six billion, two hundred eleven million, one hundred one thousand, two hundred thirty".