21058171392 has 80 divisors (see below), whose sum is σ = 56160637632. Its totient is φ = 7011840000.

The previous prime is 21058171367. The next prime is 21058171399. The reversal of 21058171392 is 29317185012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21058171392.

It is not an unprimeable number, because it can be changed into a prime (21058171399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1524517 + ... + 1538267.

Almost surely, 2^21058171392 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 21058171392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28080318816).

21058171392 is an abundant number, since it is smaller than the sum of its proper divisors (35102466240).

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

21058171392 is an equidigital number, since it uses as much as digits as its factorization.

21058171392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14769 (or 14753 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 39.

The spelling of 21058171392 in words is "twenty-one billion, fifty-eight million, one hundred seventy-one thousand, three hundred ninety-two".