31223240 has 32 divisors (see below), whose sum is σ = 70417080. Its totient is φ = 12460032.

The previous prime is 31223239. The next prime is 31223243. The reversal of 31223240 is 4232213.

It can be written as a sum of positive squares in 4 ways, for example, as 31158724 + 64516 = 5582^2 + 254^2 .

It is not an unprimeable number, because it can be changed into a prime (31223243) 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, 26504 + ... + 27656.

Almost surely, 2^31223240 is an apocalyptic number.

It is an amenable number.

31223240 is an abundant number, since it is smaller than the sum of its proper divisors (39193840).

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

31223240 is a wasteful number, since it uses less digits than its factorization.

31223240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1841 (or 1837 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 31223240 is about 5587.7759439691. The cubic root of 31223240 is about 314.8903288321.

Adding to 31223240 its reverse (4232213), we get a palindrome (35455453).

The spelling of 31223240 in words is "thirty-one million, two hundred twenty-three thousand, two hundred forty".