31281648 has 40 divisors (see below), whose sum is σ = 81186768. Its totient is φ = 10378752.

The previous prime is 31281643. The next prime is 31281661. The reversal of 31281648 is 84618213.

It is a Cunningham number, because it is equal to 5593²-1.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31281643) 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, 9786 + ... + 12582.

Almost surely, 2^31281648 is an apocalyptic number.

It is an amenable number.

31281648 is an abundant number, since it is smaller than the sum of its proper divisors (49905120).

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

31281648 is a wasteful number, since it uses less digits than its factorization.

31281648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3041 (or 3035 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 31281648 is about 5592.9999106025. Note that the first 4 decimals coincide. The cubic root of 31281648 is about 315.0865572160.

The spelling of 31281648 in words is "thirty-one million, two hundred eighty-one thousand, six hundred forty-eight".