31028140 has 96 divisors (see below), whose sum is σ = 80720640. Its totient is φ = 9849600.

The previous prime is 31028093. The next prime is 31028143. The reversal of 31028140 is 4182013.

31028140 = T₁ + T₂ + ... + T₅₇₀.

31028140 is a nontrivial binomial coefficient, being equal to C(572, 3).

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (31028143) by changing a digit.

It is the 570-th tetrahedral number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54055 + ... + 54625.

It is an arithmetic number, because the mean of its divisors is an integer number (840840).

Almost surely, 2^31028140 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 31028140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40360320).

31028140 is an abundant number, since it is smaller than the sum of its proper divisors (49692500).

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

31028140 is a wasteful number, since it uses less digits than its factorization.

31028140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 623 (or 621 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 31028140 is about 5570.2908362131. The cubic root of 31028140 is about 314.2330885912.

The spelling of 31028140 in words is "thirty-one million, twenty-eight thousand, one hundred forty".