861381031 has 16 divisors (see below), whose sum is σ = 1010870784. Its totient is φ = 718621344.

The previous prime is 861381029. The next prime is 861381043. The reversal of 861381031 is 130183168.

It is not a de Polignac number, because 861381031 - 2¹ = 861381029 is a prime.

It is a super-2 number, since 2×861381031² = 1483954561133245922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 861380984 and 861381002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861381331) by changing a digit.

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, 83310 + ... + 93076.

It is an arithmetic number, because the mean of its divisors is an integer number (63179424).

Almost surely, 2^861381031 is an apocalyptic number.

861381031 is a deficient number, since it is larger than the sum of its proper divisors (149489753).

861381031 is a wasteful number, since it uses less digits than its factorization.

861381031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10110.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 861381031 is about 29349.2935349388. The cubic root of 861381031 is about 951.4773066800.

The spelling of 861381031 in words is "eight hundred sixty-one million, three hundred eighty-one thousand, thirty-one".