20396740 has 72 divisors (see below), whose sum is σ = 53692632. Its totient is φ = 6451200.

The previous prime is 20396689. The next prime is 20396741. The reversal of 20396740 is 4769302.

It can be written as a sum of positive squares in 4 ways, for example, as 4588164 + 15808576 = 2142^2 + 3976^2 .

It is not an unprimeable number, because it can be changed into a prime (20396741) 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 23 ways as a sum of consecutive naturals, for example, 11940 + ... + 13540.

It is an arithmetic number, because the mean of its divisors is an integer number (745731).

Almost surely, 2^20396740 is an apocalyptic number.

20396740 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 20396740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26846316).

20396740 is an abundant number, since it is smaller than the sum of its proper divisors (33295892).

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

20396740 is a wasteful number, since it uses less digits than its factorization.

20396740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637 (or 1628 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 20396740 is about 4516.2750137696. The cubic root of 20396740 is about 273.2248859226.

The spelling of 20396740 in words is "twenty million, three hundred ninety-six thousand, seven hundred forty".