21453146550 has 144 divisors (see below), whose sum is σ = 64064368368. Its totient is φ = 5102572800.

The previous prime is 21453146489. The next prime is 21453146567. The reversal of 21453146550 is 5564135412.

21453146550 is a `hidden beast` number, since 2 + 14 + 53 + 1 + 46 + 550 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 221464 + ... + 303236.

It is an arithmetic number, because the mean of its divisors is an integer number (444891447).

Almost surely, 2^21453146550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21453146550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32032184184).

21453146550 is an abundant number, since it is smaller than the sum of its proper divisors (42611221818).

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

21453146550 is a wasteful number, since it uses less digits than its factorization.

21453146550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81855 (or 81847 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 21453146550 in words is "twenty-one billion, four hundred fifty-three million, one hundred forty-six thousand, five hundred fifty".