861928309 has 16 divisors (see below), whose sum is σ = 971841024. Its totient is φ = 757339200.

The previous prime is 861928261. The next prime is 861928337. The reversal of 861928309 is 903829168.

It is a cyclic number.

It is not a de Polignac number, because 861928309 - 2⁷ = 861928181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861928409) 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, 508267 + ... + 509959.

It is an arithmetic number, because the mean of its divisors is an integer number (60740064).

Almost surely, 2^861928309 is an apocalyptic number.

It is an amenable number.

861928309 is a deficient number, since it is larger than the sum of its proper divisors (109912715).

861928309 is a wasteful number, since it uses less digits than its factorization.

861928309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3228.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 861928309 is about 29358.6155838452. The cubic root of 861928309 is about 951.6787708936.

The spelling of 861928309 in words is "eight hundred sixty-one million, nine hundred twenty-eight thousand, three hundred nine".