21894691392 has 560 divisors, whose sum is σ = 79603518720. Its totient is φ = 5813710848.

The previous prime is 21894691361. The next prime is 21894691393. The reversal of 21894691392 is 29319649812.

21894691392 is a `hidden beast` number, since 2 + 1 + 89 + 469 + 13 + 92 = 666.

It is a super-2 number, since 2×21894691392² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21894691393) 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 79 ways as a sum of consecutive naturals, for example, 30880734 + ... + 30881442.

Almost surely, 2^21894691392 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 21894691392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39801759360).

21894691392 is an abundant number, since it is smaller than the sum of its proper divisors (57708827328).

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

21894691392 is a wasteful number, since it uses less digits than its factorization.

21894691392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800 (or 781 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 54.

The spelling of 21894691392 in words is "twenty-one billion, eight hundred ninety-four million, six hundred ninety-one thousand, three hundred ninety-two".