21493002473550 has 576 divisors, whose sum is σ = 64334182348800. Its totient is φ = 5315611392000.

The previous prime is 21493002473489. The next prime is 21493002473563. The reversal of 21493002473550 is 5537420039412.

It is a happy number.

21493002473550 is a `hidden beast` number, since 2 + 1 + 4 + 9 + 3 + 0 + 0 + 24 + 73 + 550 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 21493002473496 and 21493002473505.

It is a congruent number.

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, 11438531511 + ... + 11438533389.

It is an arithmetic number, because the mean of its divisors is an integer number (111691288800).

Almost surely, 2^{21493002473550} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21493002473550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32167091174400).

21493002473550 is an abundant number, since it is smaller than the sum of its proper divisors (42841179875250).

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

21493002473550 is a wasteful number, since it uses less digits than its factorization.

21493002473550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2703 (or 2686 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The spelling of 21493002473550 in words is "twenty-one trillion, four hundred ninety-three billion, two million, four hundred seventy-three thousand, five hundred fifty".