18961518977279 has 4 divisors (see below), whose sum is σ = 19282900654920. Its totient is φ = 18640137299640.

The previous prime is 18961518977251. The next prime is 18961518977309. The reversal of 18961518977279 is 97277981516981.

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 18961518977279 - 2¹² = 18961518973183 is a prime.

It is a super-3 number, since 3×18961518977279³ (a number of 41 digits) contains 333 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 (18961518977249) 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, 160690838732 + ... + 160690838849.

It is an arithmetic number, because the mean of its divisors is an integer number (4820725163730).

Almost surely, 2^{18961518977279} is an apocalyptic number.

18961518977279 is a deficient number, since it is larger than the sum of its proper divisors (321381677641).

18961518977279 is an equidigital number, since it uses as much as digits as its factorization.

18961518977279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321381677640.

The product of its digits is 960180480, while the sum is 80.

The spelling of 18961518977279 in words is "eighteen trillion, nine hundred sixty-one billion, five hundred eighteen million, nine hundred seventy-seven thousand, two hundred seventy-nine".