815504040 has 192 divisors, whose sum is σ = 2869251840. Its totient is φ = 199687680.

The previous prime is 815504029. The next prime is 815504051. The reversal of 815504040 is 40405518.

It is an interprime number because it is at equal distance from previous prime (815504029) and next prime (815504051).

It is a junction number, because it is equal to n+sod(n) for n = 815503995 and 815504013.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1267959 + ... + 1268601.

It is an arithmetic number, because the mean of its divisors is an integer number (14944020).

Almost surely, 2^815504040 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 815504040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1434625920).

815504040 is an abundant number, since it is smaller than the sum of its proper divisors (2053747800).

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

815504040 is a wasteful number, since it uses less digits than its factorization.

815504040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944 (or 937 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 815504040 is about 28557.0313583187. The cubic root of 815504040 is about 934.2763863743.

Adding to 815504040 its reverse (40405518), we get a palindrome (855909558).

The spelling of 815504040 in words is "eight hundred fifteen million, five hundred four thousand, forty".