855029101561 has 4 divisors (see below), whose sum is σ = 855031275124. Its totient is φ = 855026928000.

The previous prime is 855029101529. The next prime is 855029101631. The reversal of 855029101561 is 165101920558.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165101920558 = 2 ⋅82550960279.

It can be written as a sum of positive squares in 2 ways, for example, as 327720755961 + 527308345600 = 572469^2 + 726160^2 .

It is a cyclic number.

It is not a de Polignac number, because 855029101561 - 2⁵ = 855029101529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (855029101501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313140 + ... + 1344661.

It is an arithmetic number, because the mean of its divisors is an integer number (213757818781).

It is a Poulet number, since it divides 2^855029101560-1.

Almost surely, 2^855029101561 is an apocalyptic number.

855029101561 is the 413529-th centered decagonal number.

It is an amenable number.

855029101561 is a deficient number, since it is larger than the sum of its proper divisors (2173563).

855029101561 is a wasteful number, since it uses less digits than its factorization.

855029101561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2173562.

The product of its (nonzero) digits is 108000, while the sum is 43.

The spelling of 855029101561 in words is "eight hundred fifty-five billion, twenty-nine million, one hundred one thousand, five hundred sixty-one".