18531343990511 has 4 divisors (see below), whose sum is σ = 20216011626024. Its totient is φ = 16846676355000.

The previous prime is 18531343990487. The next prime is 18531343990517. The reversal of 18531343990511 is 11509934313581.

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 18531343990511 - 2¹⁴ = 18531343974127 is a prime.

It is a super-2 number, since 2×18531343990511² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18531343990517) 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, 842333817740 + ... + 842333817761.

It is an arithmetic number, because the mean of its divisors is an integer number (5054002906506).

Almost surely, 2^{18531343990511} is an apocalyptic number.

18531343990511 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18531343990511 is a deficient number, since it is larger than the sum of its proper divisors (1684667635513).

18531343990511 is a wasteful number, since it uses less digits than its factorization.

18531343990511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1684667635512.

The product of its (nonzero) digits is 1749600, while the sum is 53.

The spelling of 18531343990511 in words is "eighteen trillion, five hundred thirty-one billion, three hundred forty-three million, nine hundred ninety thousand, five hundred eleven".