21655404406350 has 1536 divisors, whose sum is σ = 75757151232000. Its totient is φ = 4507644556800.

The previous prime is 21655404406319. The next prime is 21655404406403. The reversal of 21655404406350 is 5360440455612.

21655404406350 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 5 + 4 + 0 + 4 + 4 + 0 + 635 + 0 = 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 = 21655404406296 and 21655404406305.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 767 ways as a sum of consecutive naturals, for example, 26185494637 + ... + 26185495463.

It is an arithmetic number, because the mean of its divisors is an integer number (49321062000).

Almost surely, 2^{21655404406350} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21655404406350, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37878575616000).

21655404406350 is an abundant number, since it is smaller than the sum of its proper divisors (54101746825650).

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

21655404406350 is a wasteful number, since it uses less digits than its factorization.

21655404406350 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972 (or 939 counting only the distinct ones).

The product of its (nonzero) digits is 1728000, while the sum is 45.

The spelling of 21655404406350 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred four million, four hundred six thousand, three hundred fifty".