21910320 has 60 divisors (see below), whose sum is σ = 73584576. Its totient is φ = 5842560.

The previous prime is 21910309. The next prime is 21910321. The reversal of 21910320 is 2301912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21910293 and 21910302.

It is not an unprimeable number, because it can be changed into a prime (21910321) by changing a digit.

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, 14496 + ... + 15935.

Almost surely, 2^21910320 is an apocalyptic number.

21910320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21910320 is an abundant number, since it is smaller than the sum of its proper divisors (51674256).

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

21910320 is a wasteful number, since it uses less digits than its factorization.

21910320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30450 (or 30441 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 21910320 is about 4680.8460773668. The cubic root of 21910320 is about 279.8226768411.

The spelling of 21910320 in words is "twenty-one million, nine hundred ten thousand, three hundred twenty".