1011815440 has 20 divisors (see below), whose sum is σ = 2352471084. Its totient is φ = 404726144.

The previous prime is 1011815429. The next prime is 1011815449. The reversal of 1011815440 is 445181101.

It can be written as a sum of positive squares in 2 ways, for example, as 151683856 + 860131584 = 12316^2 + 29328^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (1011815449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6323767 + ... + 6323926.

Almost surely, 2^1011815440 is an apocalyptic number.

1011815440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1011815440 is an abundant number, since it is smaller than the sum of its proper divisors (1340655644).

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

1011815440 is a wasteful number, since it uses less digits than its factorization.

1011815440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12647706 (or 12647700 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 1011815440 is about 31809.0465119595. The cubic root of 1011815440 is about 1003.9230694005.

Adding to 1011815440 its reverse (445181101), we get a palindrome (1456996541).

The spelling of 1011815440 in words is "one billion, eleven million, eight hundred fifteen thousand, four hundred forty".