21158645392 has 80 divisors (see below), whose sum is σ = 43130489472. Its totient is φ = 10036224000.

The previous prime is 21158645371. The next prime is 21158645393. The reversal of 21158645392 is 29354685112.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is not an unprimeable number, because it can be changed into a prime (21158645393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36669808 + ... + 36670384.

Almost surely, 2^21158645392 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 21158645392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21565244736).

21158645392 is an abundant number, since it is smaller than the sum of its proper divisors (21971844080).

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

21158645392 is a wasteful number, since it uses less digits than its factorization.

21158645392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1256 (or 1250 counting only the distinct ones).

The product of its digits is 518400, while the sum is 46.

The spelling of 21158645392 in words is "twenty-one billion, one hundred fifty-eight million, six hundred forty-five thousand, three hundred ninety-two".