861188856720 has 80 divisors (see below), whose sum is σ = 2669883021312. Its totient is φ = 229633367040.

The previous prime is 861188856677. The next prime is 861188856761. The reversal of 861188856720 is 27658881168.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3301809 + ... + 3553071.

Almost surely, 2^861188856720 is an apocalyptic number.

861188856720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

861188856720 is an abundant number, since it is smaller than the sum of its proper divisors (1808694164592).

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

861188856720 is a wasteful number, since it uses less digits than its factorization.

861188856720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265560 (or 265554 counting only the distinct ones).

The product of its (nonzero) digits is 10321920, while the sum is 60.

The spelling of 861188856720 in words is "eight hundred sixty-one billion, one hundred eighty-eight million, eight hundred fifty-six thousand, seven hundred twenty".