21955480 has 48 divisors (see below), whose sum is σ = 50572080. Its totient is φ = 8577792.

The previous prime is 21955463. The next prime is 21955559. The reversal of 21955480 is 8455912.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 213109 + ... + 213211.

It is an arithmetic number, because the mean of its divisors is an integer number (1053585).

Almost surely, 2^21955480 is an apocalyptic number.

21955480 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 21955480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25286040).

21955480 is an abundant number, since it is smaller than the sum of its proper divisors (28616600).

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

21955480 is a wasteful number, since it uses less digits than its factorization.

21955480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 21955480 is about 4685.6675084773. The cubic root of 21955480 is about 280.0147951366.

The spelling of 21955480 in words is "twenty-one million, nine hundred fifty-five thousand, four hundred eighty".