21154444000 has 96 divisors (see below), whose sum is σ = 52357215456. Its totient is φ = 8399795200.

The previous prime is 21154443949. The next prime is 21154444001. The reversal of 21154444000 is 44445112.

It is a super-3 number, since 3×21154444000³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154444001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 528699 + ... + 567301.

It is an arithmetic number, because the mean of its divisors is an integer number (545387661).

Almost surely, 2^21154444000 is an apocalyptic number.

21154444000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21154444000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26178607728).

21154444000 is an abundant number, since it is smaller than the sum of its proper divisors (31202771456).

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

21154444000 is a wasteful number, since it uses less digits than its factorization.

21154444000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38765 (or 38747 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21154444000 its reverse (44445112), we get a palindrome (21198889112).

The spelling of 21154444000 in words is "twenty-one billion, one hundred fifty-four million, four hundred forty-four thousand".