21657770016450 has 192 divisors, whose sum is σ = 56326734858240. Its totient is φ = 5502571925760.

The previous prime is 21657770016433. The next prime is 21657770016457. The reversal of 21657770016450 is 5461007775612.

It is a happy number.

It is a super-3 number, since 3×21657770016450³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21657770016393 and 21657770016402.

It is not an unprimeable number, because it can be changed into a prime (21657770016457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 42036604 + ... + 42548696.

It is an arithmetic number, because the mean of its divisors is an integer number (293368410720).

Almost surely, 2^{21657770016450} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21657770016450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28163367429120).

21657770016450 is an abundant number, since it is smaller than the sum of its proper divisors (34668964841790).

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

21657770016450 is a wasteful number, since it uses less digits than its factorization.

21657770016450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512313 (or 512308 counting only the distinct ones).

The product of its (nonzero) digits is 2469600, while the sum is 51.

The spelling of 21657770016450 in words is "twenty-one trillion, six hundred fifty-seven billion, seven hundred seventy million, sixteen thousand, four hundred fifty".