21965553792 has 576 divisors, whose sum is σ = 81424488600. Its totient is φ = 5629575168.

The previous prime is 21965553791. The next prime is 21965553793. The reversal of 21965553792 is 29735556912.

21965553792 is a `hidden beast` number, since 2 + 19 + 6 + 5 + 5 + 537 + 92 = 666.

It is an interprime number because it is at equal distance from previous prime (21965553791) and next prime (21965553793).

It can be written as a sum of positive squares in 4 ways, for example, as 21510328896 + 455224896 = 146664^2 + 21336^2 .

It is a tau number, because it is divible by the number of its divisors (576).

It is not an unprimeable number, because it can be changed into a prime (21965553791) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 27151084 + ... + 27151892.

Almost surely, 2^21965553792 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 21965553792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40712244300).

21965553792 is an abundant number, since it is smaller than the sum of its proper divisors (59458934808).

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

21965553792 is a wasteful number, since it uses less digits than its factorization.

21965553792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 893 (or 871 counting only the distinct ones).

The product of its digits is 5103000, while the sum is 54.

The spelling of 21965553792 in words is "twenty-one billion, nine hundred sixty-five million, five hundred fifty-three thousand, seven hundred ninety-two".