31440000 has 160 divisors (see below), whose sum is σ = 105153840. Its totient is φ = 8320000.

The previous prime is 31439977. The next prime is 31440001. The reversal of 31440000 is 4413.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (31440001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 239935 + ... + 240065.

Almost surely, 2^31440000 is an apocalyptic number.

31440000 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 31440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52576920).

31440000 is an abundant number, since it is smaller than the sum of its proper divisors (73713840).

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

31440000 is an equidigital number, since it uses as much as digits as its factorization.

31440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 31440000 is about 5607.1383075505. The cubic root of 31440000 is about 315.6173330817.

Adding to 31440000 its reverse (4413), we get a palindrome (31444413).

The spelling of 31440000 in words is "thirty-one million, four hundred forty thousand".