5618161800 has 72 divisors (see below), whose sum is σ = 18867666090. Its totient is φ = 1498176000.

The previous prime is 5618161789. The next prime is 5618161877. The reversal of 5618161800 is 81618165.

5618161800 is a `hidden beast` number, since 561 + 8 + 16 + 1 + 80 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 5131429956 + 486731844 = 71634^2 + 22062^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1558801 + ... + 1562400.

Almost surely, 2^5618161800 is an apocalyptic number.

5618161800 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

5618161800 is an abundant number, since it is smaller than the sum of its proper divisors (13249504290).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

5618161800 is a wasteful number, since it uses less digits than its factorization.

5618161800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3121223 (or 3121211 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 5618161800 is about 74954.3981364669. The cubic root of 5618161800 is about 1777.7256860026.

Adding to 5618161800 its reverse (81618165), we get a palindrome (5699779965).

The spelling of 5618161800 in words is "five billion, six hundred eighteen million, one hundred sixty-one thousand, eight hundred".