21426131072 has 64 divisors (see below), whose sum is σ = 43666983360. Its totient is φ = 10468224000.

The previous prime is 21426131057. The next prime is 21426131093. The reversal of 21426131072 is 27013162412.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1696493 + ... + 1709075.

It is an arithmetic number, because the mean of its divisors is an integer number (682296615).

Almost surely, 2^21426131072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21426131072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21833491680).

21426131072 is an abundant number, since it is smaller than the sum of its proper divisors (22240852288).

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

21426131072 is a wasteful number, since it uses less digits than its factorization.

21426131072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12901 (or 12889 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

Adding to 21426131072 its reverse (27013162412), we get a palindrome (48439293484).

The spelling of 21426131072 in words is "twenty-one billion, four hundred twenty-six million, one hundred thirty-one thousand, seventy-two".