20397660 has 48 divisors (see below), whose sum is σ = 57908256. Its totient is φ = 5363712.

The previous prime is 20397647. The next prime is 20397673. The reversal of 20397660 is 6679302.

It is an interprime number because it is at equal distance from previous prime (20397647) and next prime (20397673).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2052 + ... + 6708.

It is an arithmetic number, because the mean of its divisors is an integer number (1206422).

Almost surely, 2^20397660 is an apocalyptic number.

20397660 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 20397660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28954128).

20397660 is an abundant number, since it is smaller than the sum of its proper divisors (37510596).

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

20397660 is a wasteful number, since it uses less digits than its factorization.

20397660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4742 (or 4740 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 33.

The square root of 20397660 is about 4516.3768664716. The cubic root of 20397660 is about 273.2289938195.

The spelling of 20397660 in words is "twenty million, three hundred ninety-seven thousand, six hundred sixty".