20380720 has 40 divisors (see below), whose sum is σ = 47581776. Its totient is φ = 8118528.

The previous prime is 20380699. The next prime is 20380721. The reversal of 20380720 is 2708302.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 20380691 and 20380700.

It is not an unprimeable number, because it can be changed into a prime (20380721) 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 7 ways as a sum of consecutive naturals, for example, 29499 + ... + 30181.

Almost surely, 2^20380720 is an apocalyptic number.

20380720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20380720 is an abundant number, since it is smaller than the sum of its proper divisors (27201056).

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

20380720 is a wasteful number, since it uses less digits than its factorization.

20380720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069 (or 1063 counting only the distinct ones).

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

The square root of 20380720 is about 4514.5010798537. The cubic root of 20380720 is about 273.1533351239.

The spelling of 20380720 in words is "twenty million, three hundred eighty thousand, seven hundred twenty".