861816631500 has 1296 divisors, whose sum is σ = 3254742245664. Its totient is φ = 198871200000.

The previous prime is 861816631493. The next prime is 861816631519. The reversal of 861816631500 is 5136618168.

861816631500 is a `hidden beast` number, since 8 + 6 + 1 + 8 + 1 + 6 + 631 + 5 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 14128141470 + ... + 14128141530.

Almost surely, 2^861816631500 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 861816631500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1627371122832).

861816631500 is an abundant number, since it is smaller than the sum of its proper divisors (2392925614164).

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

861816631500 is a wasteful number, since it uses less digits than its factorization.

861816631500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 861816631500 in words is "eight hundred sixty-one billion, eight hundred sixteen million, six hundred thirty-one thousand, five hundred".