73128400 has 30 divisors (see below), whose sum is σ = 175691942. Its totient is φ = 29251200.

The previous prime is 73128389. The next prime is 73128409. The reversal of 73128400 is 482137.

It can be written as a sum of positive squares in 3 ways, for example, as 2702736 + 70425664 = 1644^2 + 8392^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73128409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 91011 + ... + 91810.

Almost surely, 2^73128400 is an apocalyptic number.

It is an amenable number.

73128400 is an abundant number, since it is smaller than the sum of its proper divisors (102563542).

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

73128400 is a wasteful number, since it uses less digits than its factorization.

73128400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182839 (or 182828 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 73128400 is about 8551.5144857505. The cubic root of 73128400 is about 418.1788113434.

The spelling of 73128400 in words is "seventy-three million, one hundred twenty-eight thousand, four hundred".