20870320 has 20 divisors (see below), whose sum is σ = 48523680. Its totient is φ = 8348096.

The previous prime is 20870293. The next prime is 20870321. The reversal of 20870320 is 2307802.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 20870291 and 20870300.

It is not an unprimeable number, because it can be changed into a prime (20870321) 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, 130360 + ... + 130519.

It is an arithmetic number, because the mean of its divisors is an integer number (2426184).

Almost surely, 2^20870320 is an apocalyptic number.

20870320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20870320 is an abundant number, since it is smaller than the sum of its proper divisors (27653360).

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

20870320 is a wasteful number, since it uses less digits than its factorization.

20870320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260892 (or 260886 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 20870320 is about 4568.4045355025. The cubic root of 20870320 is about 275.3233441818.

The spelling of 20870320 in words is "twenty million, eight hundred seventy thousand, three hundred twenty".