31423120 has 40 divisors (see below), whose sum is σ = 73801080. Its totient is φ = 12441600.

The previous prime is 31423111. The next prime is 31423127. The reversal of 31423120 is 2132413.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14017536 + 17405584 = 3744^2 + 4172^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 31423094 and 31423103.

It is not an unprimeable number, because it can be changed into a prime (31423127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6136 + ... + 10024.

It is an arithmetic number, because the mean of its divisors is an integer number (1845027).

Almost surely, 2^31423120 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 31423120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36900540).

31423120 is an abundant number, since it is smaller than the sum of its proper divisors (42377960).

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

31423120 is a wasteful number, since it uses less digits than its factorization.

31423120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4003 (or 3997 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31423120 is about 5605.6328813079. The cubic root of 31423120 is about 315.5608384430.

Adding to 31423120 its reverse (2132413), we get a palindrome (33555533).

The spelling of 31423120 in words is "thirty-one million, four hundred twenty-three thousand, one hundred twenty".