18491018491 has 24 divisors (see below), whose sum is σ = 20882842704. Its totient is φ = 16236000000.

The previous prime is 18491018449. The next prime is 18491018537. The reversal of 18491018491 is 19481019481.

It is a happy number.

It is not a de Polignac number, because 18491018491 - 2⁷ = 18491018363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18491018401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1862641 + ... + 1872541.

It is an arithmetic number, because the mean of its divisors is an integer number (870118446).

Almost surely, 2^18491018491 is an apocalyptic number.

18491018491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18491018491 is a deficient number, since it is larger than the sum of its proper divisors (2391824213).

18491018491 is a wasteful number, since it uses less digits than its factorization.

18491018491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10095 (or 10054 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 46.

It can be divided in two parts, 184910 and 18491, that added together give a square (203401 = 451²).

The spelling of 18491018491 in words is "eighteen billion, four hundred ninety-one million, eighteen thousand, four hundred ninety-one".