21155106336 has 576 divisors, whose sum is σ = 73842451200. Its totient is φ = 5276823552.

The previous prime is 21155106299. The next prime is 21155106337. The reversal of 21155106336 is 63360155112.

It is a junction number, because it is equal to n+sod(n) for n = 21155106297 and 21155106306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21155106337) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 237697780 + ... + 237697868.

It is an arithmetic number, because the mean of its divisors is an integer number (128198700).

Almost surely, 2^21155106336 is an apocalyptic number.

21155106336 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21155106336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36921225600).

21155106336 is an abundant number, since it is smaller than the sum of its proper divisors (52687344864).

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

21155106336 is a wasteful number, since it uses less digits than its factorization.

21155106336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 33.

The spelling of 21155106336 in words is "twenty-one billion, one hundred fifty-five million, one hundred six thousand, three hundred thirty-six".