861553853 has 4 divisors (see below), whose sum is σ = 861738108. Its totient is φ = 861369600.

The previous prime is 861553817. The next prime is 861553859. The reversal of 861553853 is 358355168.

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

It can be written as a sum of positive squares in 2 ways, for example, as 704477764 + 157076089 = 26542^2 + 12533^2 .

It is a cyclic number.

It is not a de Polignac number, because 861553853 - 2⁶ = 861553789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861553859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84926 + ... + 94527.

It is an arithmetic number, because the mean of its divisors is an integer number (215434527).

Almost surely, 2^861553853 is an apocalyptic number.

It is an amenable number.

861553853 is a deficient number, since it is larger than the sum of its proper divisors (184255).

861553853 is a wasteful number, since it uses less digits than its factorization.

861553853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184254.

The product of its digits is 432000, while the sum is 44.

The square root of 861553853 is about 29352.2376148736. The cubic root of 861553853 is about 951.5409352057.

The spelling of 861553853 in words is "eight hundred sixty-one million, five hundred fifty-three thousand, eight hundred fifty-three".