31478720 has 224 divisors, whose sum is σ = 98316288. Its totient is φ = 9326592.

The previous prime is 31478719. The next prime is 31478737. The reversal of 31478720 is 2787413.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 669737 + ... + 669783.

It is an arithmetic number, because the mean of its divisors is an integer number (438912).

Almost surely, 2^31478720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31478720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49158144).

31478720 is an abundant number, since it is smaller than the sum of its proper divisors (66837568).

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

31478720 is a wasteful number, since it uses less digits than its factorization.

31478720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 31478720 is about 5610.5899868017. The cubic root of 31478720 is about 315.7468463319.

The spelling of 31478720 in words is "thirty-one million, four hundred seventy-eight thousand, seven hundred twenty".