811487640 has 64 divisors (see below), whose sum is σ = 2448597600. Its totient is φ = 215140352.

The previous prime is 811487623. The next prime is 811487653. The reversal of 811487640 is 46784118.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1216 + ... + 40304.

Almost surely, 2^811487640 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 811487640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1224298800).

811487640 is an abundant number, since it is smaller than the sum of its proper divisors (1637109960).

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

811487640 is a wasteful number, since it uses less digits than its factorization.

811487640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39276 (or 39272 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 39.

The square root of 811487640 is about 28486.6221233757. The cubic root of 811487640 is about 932.7400747986.

It can be divided in two parts, 81148 and 7640, that added together give a palindrome (88788).

The spelling of 811487640 in words is "eight hundred eleven million, four hundred eighty-seven thousand, six hundred forty".