618869861 has 4 divisors (see below), whose sum is σ = 623023500. Its totient is φ = 614716224.

The previous prime is 618869851. The next prime is 618869869. The reversal of 618869861 is 168968816.

It is a happy number.

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 163047361 + 455822500 = 12769^2 + 21350^2 .

It is a cyclic number.

It is not a de Polignac number, because 618869861 - 2¹⁰ = 618868837 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 (618869869) 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, 2076596 + ... + 2076893.

It is an arithmetic number, because the mean of its divisors is an integer number (155755875).

Almost surely, 2^618869861 is an apocalyptic number.

It is an amenable number.

618869861 is a deficient number, since it is larger than the sum of its proper divisors (4153639).

618869861 is a wasteful number, since it uses less digits than its factorization.

618869861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4153638.

The product of its digits is 995328, while the sum is 53.

The square root of 618869861 is about 24877.0951077492. The cubic root of 618869861 is about 852.1834801600.

The spelling of 618869861 in words is "six hundred eighteen million, eight hundred sixty-nine thousand, eight hundred sixty-one".