18019512461 has 4 divisors (see below), whose sum is σ = 18021701472. Its totient is φ = 18017323452.

The previous prime is 18019512439. The next prime is 18019512473. The reversal of 18019512461 is 16421591081.

It is a happy number.

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 18019512461 - 2²² = 18015318157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18019512421) 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, 1082111 + ... + 1098636.

It is an arithmetic number, because the mean of its divisors is an integer number (4505425368).

Almost surely, 2^18019512461 is an apocalyptic number.

It is an amenable number.

18019512461 is a deficient number, since it is larger than the sum of its proper divisors (2189011).

18019512461 is an equidigital number, since it uses as much as digits as its factorization.

18019512461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2189010.

The product of its (nonzero) digits is 17280, while the sum is 38.

The spelling of 18019512461 in words is "eighteen billion, nineteen million, five hundred twelve thousand, four hundred sixty-one".