21227880 has 32 divisors (see below), whose sum is σ = 63684000. Its totient is φ = 5660736.

The previous prime is 21227867. The next prime is 21227887. The reversal of 21227880 is 8872212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21227887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88330 + ... + 88569.

It is an arithmetic number, because the mean of its divisors is an integer number (1990125).

Almost surely, 2^21227880 is an apocalyptic number.

21227880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21227880 is an abundant number, since it is smaller than the sum of its proper divisors (42456120).

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

21227880 is a wasteful number, since it uses less digits than its factorization.

21227880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176913 (or 176909 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21227880 is about 4607.3723530880. The cubic root of 21227880 is about 276.8867718312.

The spelling of 21227880 in words is "twenty-one million, two hundred twenty-seven thousand, eight hundred eighty".