31471440 has 320 divisors, whose sum is σ = 131991552. Its totient is φ = 5990400.

The previous prime is 31471439. The next prime is 31471457. The reversal of 31471440 is 4417413.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 31471440.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 240175 + ... + 240305.

Almost surely, 2^31471440 is an apocalyptic number.

31471440 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 31471440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65995776).

31471440 is an abundant number, since it is smaller than the sum of its proper divisors (100520112).

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

31471440 is a wasteful number, since it uses less digits than its factorization.

31471440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 31471440 is about 5609.9411761622. The cubic root of 31471440 is about 315.7225038103.

Adding to 31471440 its reverse (4417413), we get a palindrome (35888853).

The spelling of 31471440 in words is "thirty-one million, four hundred seventy-one thousand, four hundred forty".