20397960 has 256 divisors, whose sum is σ = 79315200. Its totient is φ = 4608000.

The previous prime is 20397947. The next prime is 20397961. The reversal of 20397960 is 6979302.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20397961) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 201910 + ... + 202010.

It is an arithmetic number, because the mean of its divisors is an integer number (309825).

Almost surely, 2^20397960 is an apocalyptic number.

20397960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20397960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39657600).

20397960 is an abundant number, since it is smaller than the sum of its proper divisors (58917240).

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

20397960 is a wasteful number, since it uses less digits than its factorization.

20397960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 20397960 is about 4516.4100788126. The cubic root of 20397960 is about 273.2303333244.

It can be divided in two parts, 2039 and 7960, that added together give a palindrome (9999).

The spelling of 20397960 in words is "twenty million, three hundred ninety-seven thousand, nine hundred sixty".