1020181918191 has 4 divisors (see below), whose sum is σ = 1360242557592. Its totient is φ = 680121278792.

The previous prime is 1020181918187. The next prime is 1020181918213. The reversal of 1020181918191 is 1918191810201.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1020181918191 - 2² = 1020181918187 is a prime.

It is a super-2 number, since 2×1020181918191² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020181918391) 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, 170030319696 + ... + 170030319701.

It is an arithmetic number, because the mean of its divisors is an integer number (340060639398).

Almost surely, 2^{1020181918191} is an apocalyptic number.

1020181918191 is a deficient number, since it is larger than the sum of its proper divisors (340060639401).

1020181918191 is an equidigital number, since it uses as much as digits as its factorization.

1020181918191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340060639400.

The product of its (nonzero) digits is 10368, while the sum is 42.

The spelling of 1020181918191 in words is "one trillion, twenty billion, one hundred eighty-one million, nine hundred eighteen thousand, one hundred ninety-one".