21457264136 has 128 divisors (see below), whose sum is σ = 53411788800. Its totient is φ = 7823569920.

The previous prime is 21457264123. The next prime is 21457264177. The reversal of 21457264136 is 63146275412.

It is a junction number, because it is equal to n+sod(n) for n = 21457264093 and 21457264102.

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, 1868765 + ... + 1880211.

It is an arithmetic number, because the mean of its divisors is an integer number (417279600).

Almost surely, 2^21457264136 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 21457264136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26705894400).

21457264136 is an abundant number, since it is smaller than the sum of its proper divisors (31954524664).

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

21457264136 is a wasteful number, since it uses less digits than its factorization.

21457264136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11667 (or 11663 counting only the distinct ones).

The product of its digits is 241920, while the sum is 41.

The spelling of 21457264136 in words is "twenty-one billion, four hundred fifty-seven million, two hundred sixty-four thousand, one hundred thirty-six".