21749619880 has 16 divisors (see below), whose sum is σ = 48936644820. Its totient is φ = 8699847936.

The previous prime is 21749619863. The next prime is 21749619887. The reversal of 21749619880 is 8891694712.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21734425476 + 15194404 = 147426^2 + 3898^2 .

It is not an unprimeable number, because it can be changed into a prime (21749619887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271870209 + ... + 271870288.

Almost surely, 2^21749619880 is an apocalyptic number.

21749619880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21749619880 is an abundant number, since it is smaller than the sum of its proper divisors (27187024940).

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

21749619880 is a wasteful number, since it uses less digits than its factorization.

21749619880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543740508 (or 543740504 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 55.

The spelling of 21749619880 in words is "twenty-one billion, seven hundred forty-nine million, six hundred nineteen thousand, eight hundred eighty".