1918518631236 has 81 divisors (see below), whose sum is σ = 5070113054461. Its totient is φ = 611640647904.

The previous prime is 1918518631231. The next prime is 1918518631247. The reversal of 1918518631236 is 6321368158191.

The square root of 1918518631236 is 1385106.

It is a perfect power (a square), and thus also a powerful number.

1918518631236 is a `hidden beast` number, since 1 + 91 + 8 + 518 + 6 + 3 + 1 + 2 + 36 = 666.

It can be written as a sum of positive squares in only one way, i.e., 641745188100 + 1276773443136 = 801090^2 + 1129944^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1918518631231) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 191139610 + ... + 191149646.

Almost surely, 2^{1918518631236} is an apocalyptic number.

1918518631236 is the 1385106-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1918518631236

1918518631236 is an abundant number, since it is smaller than the sum of its proper divisors (3151594423225).

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

1918518631236 is an equidigital number, since it uses as much as digits as its factorization.

1918518631236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20130 (or 10065 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 1918518631236 in words is "one trillion, nine hundred eighteen billion, five hundred eighteen million, six hundred thirty-one thousand, two hundred thirty-six".