861913786 has 4 divisors (see below), whose sum is σ = 1292870682. Its totient is φ = 430956892.

The previous prime is 861913771. The next prime is 861913837. The reversal of 861913786 is 687319168.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 595604025 + 266309761 = 24405^2 + 16319^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215478445 + ... + 215478448.

Almost surely, 2^861913786 is an apocalyptic number.

861913786 is a deficient number, since it is larger than the sum of its proper divisors (430956896).

861913786 is a wasteful number, since it uses less digits than its factorization.

861913786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430956895.

The product of its digits is 435456, while the sum is 49.

The square root of 861913786 is about 29358.3682448463. The cubic root of 861913786 is about 951.6734257822.

The spelling of 861913786 in words is "eight hundred sixty-one million, nine hundred thirteen thousand, seven hundred eighty-six".