31448640 has 224 divisors, whose sum is σ = 110605824. Its totient is φ = 7536640.

The previous prime is 31448639. The next prime is 31448647. The reversal of 31448640 is 4684413.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 31448598 and 31448607.

It is not an unprimeable number, because it can be changed into a prime (31448647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 669097 + ... + 669143.

It is an arithmetic number, because the mean of its divisors is an integer number (493776).

Almost surely, 2^31448640 is an apocalyptic number.

31448640 is a gapful number since it is divisible by the number (30) 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 31448640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55302912).

31448640 is an abundant number, since it is smaller than the sum of its proper divisors (79157184).

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

31448640 is a wasteful number, since it uses less digits than its factorization.

31448640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 31448640 is about 5607.9087011113. The cubic root of 31448640 is about 315.6462419452.

The spelling of 31448640 in words is "thirty-one million, four hundred forty-eight thousand, six hundred forty".