21555410362122 has 128 divisors (see below), whose sum is σ = 53305488359424. Its totient is φ = 5658592255488.

The previous prime is 21555410362111. The next prime is 21555410362127. The reversal of 21555410362122 is 22126301455512.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (21555410362127) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 1419325413 + ... + 1419340599.

It is an arithmetic number, because the mean of its divisors is an integer number (416449127808).

Almost surely, 2^{21555410362122} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21555410362122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26652744179712).

21555410362122 is an abundant number, since it is smaller than the sum of its proper divisors (31750077997302).

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

21555410362122 is a wasteful number, since it uses less digits than its factorization.

21555410362122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27092.

The product of its (nonzero) digits is 144000, while the sum is 39.

The spelling of 21555410362122 in words is "twenty-one trillion, five hundred fifty-five billion, four hundred ten million, three hundred sixty-two thousand, one hundred twenty-two".