31726728 has 80 divisors (see below), whose sum is σ = 96964560. Its totient is φ = 9612000.

The previous prime is 31726727. The next prime is 31726741. The reversal of 31726728 is 82762713.

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

It is a junction number, because it is equal to n+sod(n) for n = 31726692 and 31726701.

It is not an unprimeable number, because it can be changed into a prime (31726727) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4903 + ... + 9353.

It is an arithmetic number, because the mean of its divisors is an integer number (1212057).

Almost surely, 2^31726728 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 31726728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48482280).

31726728 is an abundant number, since it is smaller than the sum of its proper divisors (65237832).

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

31726728 is a wasteful number, since it uses less digits than its factorization.

31726728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4480 (or 4467 counting only the distinct ones).

The product of its digits is 28224, while the sum is 36.

The square root of 31726728 is about 5632.6484001755. The cubic root of 31726728 is about 316.5738916894.

The spelling of 31726728 in words is "thirty-one million, seven hundred twenty-six thousand, seven hundred twenty-eight".