21870240054 has 64 divisors (see below), whose sum is σ = 49631232000. Its totient is φ = 6369103872.

The previous prime is 21870240047. The next prime is 21870240089. The reversal of 21870240054 is 45004207812.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21870239997 and 21870240024.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1702347 + ... + 1715145.

It is an arithmetic number, because the mean of its divisors is an integer number (775488000).

Almost surely, 2^21870240054 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21870240054, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24815616000).

21870240054 is an abundant number, since it is smaller than the sum of its proper divisors (27760991946).

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

21870240054 is a wasteful number, since it uses less digits than its factorization.

21870240054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13989.

The product of its (nonzero) digits is 17920, while the sum is 33.

Adding to 21870240054 its reverse (45004207812), we get a palindrome (66874447866).

The spelling of 21870240054 in words is "twenty-one billion, eight hundred seventy million, two hundred forty thousand, fifty-four".