861870155 has 8 divisors (see below), whose sum is σ = 1034723184. Its totient is φ = 689176800.

The previous prime is 861870137. The next prime is 861870167. The reversal of 861870155 is 551078168.

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

It is not a de Polignac number, because 861870155 - 2¹⁴ = 861853771 is a prime.

It is a super-3 number, since 3×861870155³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27701 + ... + 49910.

It is an arithmetic number, because the mean of its divisors is an integer number (129340398).

Almost surely, 2^861870155 is an apocalyptic number.

861870155 is a deficient number, since it is larger than the sum of its proper divisors (172853029).

861870155 is a wasteful number, since it uses less digits than its factorization.

861870155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79837.

The product of its (nonzero) digits is 67200, while the sum is 41.

The square root of 861870155 is about 29357.6251594028. The cubic root of 861870155 is about 951.6573672682.

The spelling of 861870155 in words is "eight hundred sixty-one million, eight hundred seventy thousand, one hundred fifty-five".