31028400 has 360 divisors, whose sum is σ = 126621360. Its totient is φ = 7188480.

The previous prime is 31028399. The next prime is 31028401. The reversal of 31028400 is 482013.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31028399) and next prime (31028401).

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (31028401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1825192 + ... + 1825208.

It is an arithmetic number, because the mean of its divisors is an integer number (351726).

Almost surely, 2^31028400 is an apocalyptic number.

31028400 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 31028400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63310680).

31028400 is an abundant number, since it is smaller than the sum of its proper divisors (95592960).

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

31028400 is a wasteful number, since it uses less digits than its factorization.

31028400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 31028400 is about 5570.3141742634. The cubic root of 31028400 is about 314.2339662931.

The spelling of 31028400 in words is "thirty-one million, twenty-eight thousand, four hundred".