861381807 has 16 divisors (see below), whose sum is σ = 1349298048. Its totient is φ = 481891680.

The previous prime is 861381803. The next prime is 861381817. The reversal of 861381807 is 708183168.

It is not a de Polignac number, because 861381807 - 2² = 861381803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861381803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1003513 + ... + 1004370.

It is an arithmetic number, because the mean of its divisors is an integer number (84331128).

Almost surely, 2^861381807 is an apocalyptic number.

861381807 is a deficient number, since it is larger than the sum of its proper divisors (487916241).

861381807 is a wasteful number, since it uses less digits than its factorization.

861381807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2007910.

The product of its (nonzero) digits is 64512, while the sum is 42.

The square root of 861381807 is about 29349.3067550155. The cubic root of 861381807 is about 951.4775924018.

The spelling of 861381807 in words is "eight hundred sixty-one million, three hundred eighty-one thousand, eight hundred seven".