21106251230155 has 64 divisors (see below), whose sum is σ = 31239081538560. Its totient is φ = 13330975624704.

The previous prime is 21106251230137. The next prime is 21106251230171. The reversal of 21106251230155 is 55103215260112.

It is a cyclic number.

It is not a de Polignac number, because 21106251230155 - 2⁷ = 21106251230027 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21106251230155.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 406590712 + ... + 406642618.

It is an arithmetic number, because the mean of its divisors is an integer number (488110649040).

Almost surely, 2^{21106251230155} is an apocalyptic number.

21106251230155 is a deficient number, since it is larger than the sum of its proper divisors (10132830308405).

21106251230155 is a wasteful number, since it uses less digits than its factorization.

21106251230155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53828.

The product of its (nonzero) digits is 18000, while the sum is 34.

Adding to 21106251230155 its reverse (55103215260112), we get a palindrome (76209466490267).

The spelling of 21106251230155 in words is "twenty-one trillion, one hundred six billion, two hundred fifty-one million, two hundred thirty thousand, one hundred fifty-five".