861281619146208 has 144 divisors (see below), whose sum is σ = 2638056922156656. Its totient is φ = 264971352729600.

The previous prime is 861281619146197. The next prime is 861281619146243. The reversal of 861281619146208 is 802641916182168.

It is a happy number.

861281619146208 is a `hidden beast` number, since 8 + 6 + 1 + 2 + 8 + 1 + 619 + 1 + 4 + 6 + 2 + 0 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×861281619146208² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9206908 + ... + 42512708.

It is an arithmetic number, because the mean of its divisors is an integer number (18319839737199).

Almost surely, 2^{861281619146208} 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 861281619146208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1319028461078328).

861281619146208 is an abundant number, since it is smaller than the sum of its proper divisors (1776775303010448).

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

861281619146208 is a wasteful number, since it uses less digits than its factorization.

861281619146208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33312737 (or 33312726 counting only the distinct ones).

The product of its (nonzero) digits is 15925248, while the sum is 63.

The spelling of 861281619146208 in words is "eight hundred sixty-one trillion, two hundred eighty-one billion, six hundred nineteen million, one hundred forty-six thousand, two hundred eight".