31478400 has 144 divisors (see below), whose sum is σ = 112424910. Its totient is φ = 8386560.

The previous prime is 31478399. The next prime is 31478401. The reversal of 31478400 is 487413.

It is an interprime number because it is at equal distance from previous prime (31478399) and next prime (31478401).

It can be written as a sum of positive squares in 3 ways, for example, as 30206016 + 1272384 = 5496^2 + 1128^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (31478401) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 28254 + ... + 29346.

Almost surely, 2^31478400 is an apocalyptic number.

31478400 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 31478400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56212455).

31478400 is an abundant number, since it is smaller than the sum of its proper divisors (80946510).

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

31478400 is a wasteful number, since it uses less digits than its factorization.

31478400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1123 (or 1103 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 31478400 is about 5610.5614692293. The cubic root of 31478400 is about 315.7457764098.

It can be divided in two parts, 31478 and 400, that added together give a triangular number (31878 = T₂₅₂).

The spelling of 31478400 in words is "thirty-one million, four hundred seventy-eight thousand, four hundred".