861155956749 has 8 divisors (see below), whose sum is σ = 1252590482592. Its totient is φ = 521912701040.

The previous prime is 861155956721. The next prime is 861155956757. The reversal of 861155956749 is 947659551168.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 861155956749 - 2⁹ = 861155956237 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 861155956749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861155956789) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13047817494 + ... + 13047817559.

It is an arithmetic number, because the mean of its divisors is an integer number (156573810324).

Almost surely, 2^861155956749 is an apocalyptic number.

It is an amenable number.

861155956749 is a deficient number, since it is larger than the sum of its proper divisors (391434525843).

861155956749 is a wasteful number, since it uses less digits than its factorization.

861155956749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26095635067.

The product of its digits is 81648000, while the sum is 66.

The spelling of 861155956749 in words is "eight hundred sixty-one billion, one hundred fifty-five million, nine hundred fifty-six thousand, seven hundred forty-nine".