20397740 has 24 divisors (see below), whose sum is σ = 46729872. Its totient is φ = 7417280.

The previous prime is 20397737. The next prime is 20397749. The reversal of 20397740 is 4779302.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20397697 and 20397706.

It is not an unprimeable number, because it can be changed into a prime (20397749) 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, 46139 + ... + 46578.

It is an arithmetic number, because the mean of its divisors is an integer number (1947078).

Almost surely, 2^20397740 is an apocalyptic number.

20397740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20397740 is an abundant number, since it is smaller than the sum of its proper divisors (26332132).

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

20397740 is a wasteful number, since it uses less digits than its factorization.

20397740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92737 (or 92735 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 20397740 is about 4516.3857231198. The cubic root of 20397740 is about 273.2293510221.

It can be divided in two parts, 2039 and 7740, that added together give a palindrome (9779).

The spelling of 20397740 in words is "twenty million, three hundred ninety-seven thousand, seven hundred forty".