21995320 has 16 divisors (see below), whose sum is σ = 49489560. Its totient is φ = 8798112.

The previous prime is 21995299. The next prime is 21995339. The reversal of 21995320 is 2359912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 274902 + ... + 274981.

Almost surely, 2^21995320 is an apocalyptic number.

21995320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21995320 is an abundant number, since it is smaller than the sum of its proper divisors (27494240).

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

21995320 is a wasteful number, since it uses less digits than its factorization.

21995320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549894 (or 549890 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 21995320 is about 4689.9168436125. The cubic root of 21995320 is about 280.1840626503.

The spelling of 21995320 in words is "twenty-one million, nine hundred ninety-five thousand, three hundred twenty".