21763121280 has 128 divisors (see below), whose sum is σ = 70507540800. Its totient is φ = 5708328960.

The previous prime is 21763121269. The next prime is 21763121291. The reversal of 21763121280 is 8212136712.

It is an interprime number because it is at equal distance from previous prime (21763121269) and next prime (21763121291).

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24211 + ... + 210029.

Almost surely, 2^21763121280 is an apocalyptic number.

21763121280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21763121280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35253770400).

21763121280 is an abundant number, since it is smaller than the sum of its proper divisors (48744419520).

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

21763121280 is a wasteful number, since it uses less digits than its factorization.

21763121280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185902 (or 185890 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

Adding to 21763121280 its reverse (8212136712), we get a palindrome (29975257992).

The spelling of 21763121280 in words is "twenty-one billion, seven hundred sixty-three million, one hundred twenty-one thousand, two hundred eighty".