31487872 has 64 divisors (see below), whose sum is σ = 68544000. Its totient is φ = 14321664.

The previous prime is 31487867. The next prime is 31487873. The reversal of 31487872 is 27878413.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31487873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211254 + ... + 211402.

It is an arithmetic number, because the mean of its divisors is an integer number (1071000).

Almost surely, 2^31487872 is an apocalyptic number.

31487872 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31487872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34272000).

31487872 is an abundant number, since it is smaller than the sum of its proper divisors (37056128).

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

31487872 is a wasteful number, since it uses less digits than its factorization.

31487872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 291 counting only the distinct ones).

The product of its digits is 75264, while the sum is 40.

The square root of 31487872 is about 5611.4055280295. The cubic root of 31487872 is about 315.7774430349. Note that the first 3 decimals are identical.

The spelling of 31487872 in words is "thirty-one million, four hundred eighty-seven thousand, eight hundred seventy-two".