861657089040 has 800 divisors, whose sum is σ = 3500910927360. Its totient is φ = 194088960000.

The previous prime is 861657089017. The next prime is 861657089047. The reversal of 861657089040 is 40980756168.

861657089040 is a `hidden beast` number, since 8 + 61 + 6 + 570 + 8 + 9 + 0 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (861657089047) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 95724540 + ... + 95733540.

Almost surely, 2^861657089040 is an apocalyptic number.

861657089040 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861657089040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1750455463680).

861657089040 is an abundant number, since it is smaller than the sum of its proper divisors (2639253838320).

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

861657089040 is a wasteful number, since it uses less digits than its factorization.

861657089040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9133 (or 9118 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 861657089040 in words is "eight hundred sixty-one billion, six hundred fifty-seven million, eighty-nine thousand, forty".