21493521450 has 96 divisors (see below), whose sum is σ = 59256385920. Its totient is φ = 5728723200.

The previous prime is 21493521391. The next prime is 21493521451. The reversal of 21493521450 is 5412539412.

21493521450 is a `hidden beast` number, since 2 + 1 + 4 + 93 + 521 + 45 + 0 = 666.

It is a super-2 number, since 2×21493521450² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21493521451) 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 47 ways as a sum of consecutive naturals, for example, 4953682 + ... + 4958018.

It is an arithmetic number, because the mean of its divisors is an integer number (617254020).

Almost surely, 2^21493521450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21493521450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29628192960).

21493521450 is an abundant number, since it is smaller than the sum of its proper divisors (37762864470).

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

21493521450 is a wasteful number, since it uses less digits than its factorization.

21493521450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8029 (or 8018 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 21493521450 in words is "twenty-one billion, four hundred ninety-three million, five hundred twenty-one thousand, four hundred fifty".