21755080 has 16 divisors (see below), whose sum is σ = 48949020. Its totient is φ = 8702016.

The previous prime is 21755077. The next prime is 21755089. The reversal of 21755080 is 8055712.

It can be written as a sum of positive squares in 2 ways, for example, as 21511044 + 244036 = 4638^2 + 494^2 .

It is not an unprimeable number, because it can be changed into a prime (21755089) 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, 271899 + ... + 271978.

Almost surely, 2^21755080 is an apocalyptic number.

21755080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21755080 is an abundant number, since it is smaller than the sum of its proper divisors (27193940).

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

21755080 is a wasteful number, since it uses less digits than its factorization.

21755080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543888 (or 543884 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 21755080 is about 4664.2341279142. The cubic root of 21755080 is about 279.1602390540.

The spelling of 21755080 in words is "twenty-one million, seven hundred fifty-five thousand, eighty".