21533346450 has 576 divisors, whose sum is σ = 76303866240. Its totient is φ = 4415040000.

The previous prime is 21533346413. The next prime is 21533346479. The reversal of 21533346450 is 5464333512.

21533346450 is a `hidden beast` number, since 2 + 1 + 5 + 3 + 3 + 3 + 4 + 645 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 73492504 + ... + 73492796.

It is an arithmetic number, because the mean of its divisors is an integer number (132471990).

Almost surely, 2^21533346450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21533346450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38151933120).

21533346450 is an abundant number, since it is smaller than the sum of its proper divisors (54770519790).

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

21533346450 is a wasteful number, since it uses less digits than its factorization.

21533346450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

Adding to 21533346450 its reverse (5464333512), we get a palindrome (26997679962).

The spelling of 21533346450 in words is "twenty-one billion, five hundred thirty-three million, three hundred forty-six thousand, four hundred fifty".