31201728 has 56 divisors (see below), whose sum is σ = 83423760. Its totient is φ = 10291200.

The previous prime is 31201727. The next prime is 31201739. The reversal of 31201728 is 82710213.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 31201698 and 31201707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31201727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18588 + ... + 20196.

It is an arithmetic number, because the mean of its divisors is an integer number (1489710).

Almost surely, 2^31201728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31201728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41711880).

31201728 is an abundant number, since it is smaller than the sum of its proper divisors (52222032).

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

31201728 is a wasteful number, since it uses less digits than its factorization.

31201728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1725 (or 1715 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 31201728 is about 5585.8506961787. The cubic root of 31201728 is about 314.8179951362.

The spelling of 31201728 in words is "thirty-one million, two hundred one thousand, seven hundred twenty-eight".