3621689947818 has 80 divisors (see below), whose sum is σ = 8236058430600. Its totient is φ = 1189299884544.

The previous prime is 3621689947817. The next prime is 3621689947819. The reversal of 3621689947818 is 8187499861263.

3621689947818 is a `hidden beast` number, since 3 + 6 + 2 + 1 + 68 + 99 + 478 + 1 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (3621689947817) and next prime (3621689947819).

It can be written as a sum of positive squares in 4 ways, for example, as 3549241227249 + 72448720569 = 1883943^2 + 269163^2 .

It is a super-2 number, since 2×3621689947818² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3621689947817) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 9956208 + ... + 10313556.

Almost surely, 2^{3621689947818} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3621689947818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4118029215300).

3621689947818 is an abundant number, since it is smaller than the sum of its proper divisors (4614368482782).

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

3621689947818 is a wasteful number, since it uses less digits than its factorization.

3621689947818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358293 (or 358284 counting only the distinct ones).

The product of its digits is 250822656, while the sum is 72.

The spelling of 3621689947818 in words is "three trillion, six hundred twenty-one billion, six hundred eighty-nine million, nine hundred forty-seven thousand, eight hundred eighteen".