31128823 has 6 divisors (see below), whose sum is σ = 34216112. Its totient is φ = 28298820.

The previous prime is 31128809. The next prime is 31128829. The reversal of 31128823 is 32882113.

It is not a de Polignac number, because 31128823 - 2¹³ = 31120631 is a prime.

It is a super-3 number, since 3×31128823³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31128791 and 31128800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31128829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 128511 + ... + 128752.

Almost surely, 2^31128823 is an apocalyptic number.

31128823 is a deficient number, since it is larger than the sum of its proper divisors (3087289).

31128823 is a wasteful number, since it uses less digits than its factorization.

31128823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257285 (or 257274 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 31128823 is about 5579.3210160377. The cubic root of 31128823 is about 314.5726058922.

It can be divided in two parts, 3112 and 8823, that added together give a triangular number (11935 = T₁₅₄).

The spelling of 31128823 in words is "thirty-one million, one hundred twenty-eight thousand, eight hundred twenty-three".