861351814855 has 128 divisors (see below), whose sum is σ = 1363489873920. Its totient is φ = 508211159040.

The previous prime is 861351814819. The next prime is 861351814859. The reversal of 861351814855 is 558418153168.

It is a happy number.

It is not a de Polignac number, because 861351814855 - 2²³ = 861343426247 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 861351814796 and 861351814805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861351814859) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 36537282 + ... + 36560848.

It is an arithmetic number, because the mean of its divisors is an integer number (10652264640).

Almost surely, 2^861351814855 is an apocalyptic number.

861351814855 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

861351814855 is a deficient number, since it is larger than the sum of its proper divisors (502138059065).

861351814855 is a wasteful number, since it uses less digits than its factorization.

861351814855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23729.

The product of its digits is 4608000, while the sum is 55.

The spelling of 861351814855 in words is "eight hundred sixty-one billion, three hundred fifty-one million, eight hundred fourteen thousand, eight hundred fifty-five".