866139900549 has 48 divisors (see below), whose sum is σ = 1466029730880. Its totient is φ = 449788765440.

The previous prime is 866139900547. The next prime is 866139900607. The reversal of 866139900549 is 945009931668.

It is not a de Polignac number, because 866139900549 - 2¹ = 866139900547 is a prime.

It is a super-2 number, since 2×866139900549² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 866139900492 and 866139900501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866139900541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4710667 + ... + 4891079.

It is an arithmetic number, because the mean of its divisors is an integer number (30542286060).

Almost surely, 2^866139900549 is an apocalyptic number.

It is an amenable number.

866139900549 is a deficient number, since it is larger than the sum of its proper divisors (599889830331).

866139900549 is a wasteful number, since it uses less digits than its factorization.

866139900549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183410 (or 183403 counting only the distinct ones).

The product of its (nonzero) digits is 12597120, while the sum is 60.

The spelling of 866139900549 in words is "eight hundred sixty-six billion, one hundred thirty-nine million, nine hundred thousand, five hundred forty-nine".