2118021190981 has 4 divisors (see below), whose sum is σ = 2167277497792. Its totient is φ = 2068764884172.

The previous prime is 2118021190979. The next prime is 2118021191021. The reversal of 2118021190981 is 1890911208112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2118021190981 - 2¹ = 2118021190979 is a prime.

It is a super-2 number, since 2×2118021190981² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 49256306767 = 2118021190981 / (2 + 1 + 1 + 8 + 0 + 2 + 1 + 1 + 9 + 0 + 9 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2118021190921) 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, 24628153341 + ... + 24628153426.

It is an arithmetic number, because the mean of its divisors is an integer number (541819374448).

Almost surely, 2^{2118021190981} is an apocalyptic number.

It is an amenable number.

2118021190981 is a deficient number, since it is larger than the sum of its proper divisors (49256306811).

2118021190981 is an equidigital number, since it uses as much as digits as its factorization.

2118021190981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49256306810.

The product of its (nonzero) digits is 20736, while the sum is 43.

The spelling of 2118021190981 in words is "two trillion, one hundred eighteen billion, twenty-one million, one hundred ninety thousand, nine hundred eighty-one".