20397472 has 12 divisors (see below), whose sum is σ = 40157586. Its totient is φ = 10198720.

The previous prime is 20397427. The next prime is 20397479. The reversal of 20397472 is 27479302.

It can be written as a sum of positive squares in only one way, i.e., 15397776 + 4999696 = 3924^2 + 2236^2 .

It is not an unprimeable number, because it can be changed into a prime (20397479) 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 as a sum of consecutive naturals, namely, 318679 + ... + 318742.

Almost surely, 2^20397472 is an apocalyptic number.

It is an amenable number.

20397472 is a deficient number, since it is larger than the sum of its proper divisors (19760114).

20397472 is an equidigital number, since it uses as much as digits as its factorization.

20397472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637431 (or 637423 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 34.

The square root of 20397472 is about 4516.3560532801. The cubic root of 20397472 is about 273.2281543898.

The spelling of 20397472 in words is "twenty million, three hundred ninety-seven thousand, four hundred seventy-two".