18729809949 has 32 divisors (see below), whose sum is σ = 27445017600. Its totient is φ = 11308999680.

The previous prime is 18729809941. The next prime is 18729809951. The reversal of 18729809949 is 94990892781.

It is not a de Polignac number, because 18729809949 - 2³ = 18729809941 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18729809949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18729809941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4364797 + ... + 4369085.

It is an arithmetic number, because the mean of its divisors is an integer number (857656800).

Almost surely, 2^18729809949 is an apocalyptic number.

18729809949 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18729809949 is a deficient number, since it is larger than the sum of its proper divisors (8715207651).

18729809949 is a wasteful number, since it uses less digits than its factorization.

18729809949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7665.

The product of its (nonzero) digits is 23514624, while the sum is 66.

The spelling of 18729809949 in words is "eighteen billion, seven hundred twenty-nine million, eight hundred nine thousand, nine hundred forty-nine".