21155015113254 has 96 divisors (see below), whose sum is σ = 52674770828160. Its totient is φ = 6068561990400.

The previous prime is 21155015113217. The next prime is 21155015113279. The reversal of 21155015113254 is 45231151055112.

21155015113254 is a `hidden beast` number, since 2 + 1 + 1 + 550 + 1 + 51 + 1 + 3 + 2 + 54 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2765694 + ... + 7068174.

It is an arithmetic number, because the mean of its divisors is an integer number (548695529460).

Almost surely, 2^{21155015113254} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21155015113254, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26337385414080).

21155015113254 is an abundant number, since it is smaller than the sum of its proper divisors (31519755714906).

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

21155015113254 is a wasteful number, since it uses less digits than its factorization.

21155015113254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4303826 (or 4303823 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 36.

Adding to 21155015113254 its reverse (45231151055112), we get a palindrome (66386166168366).

The spelling of 21155015113254 in words is "twenty-one trillion, one hundred fifty-five billion, fifteen million, one hundred thirteen thousand, two hundred fifty-four".