21198841776 has 420 divisors, whose sum is σ = 74163110400. Its totient is φ = 5843384064.

The previous prime is 21198841771. The next prime is 21198841799. The reversal of 21198841776 is 67714889112.

21198841776 is a `hidden beast` number, since 211 + 9 + 8 + 8 + 417 + 7 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21198841771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 16573905 + ... + 16575183.

Almost surely, 2^21198841776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21198841776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37081555200).

21198841776 is an abundant number, since it is smaller than the sum of its proper divisors (52964268624).

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

21198841776 is a wasteful number, since it uses less digits than its factorization.

21198841776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348 (or 1320 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The spelling of 21198841776 in words is "twenty-one billion, one hundred ninety-eight million, eight hundred forty-one thousand, seven hundred seventy-six".