18977898481 has 4 divisors (see below), whose sum is σ = 18978303600. Its totient is φ = 18977493364.

The previous prime is 18977898469. The next prime is 18977898503. The reversal of 18977898481 is 18489877981.

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 18977898481 - 2⁹ = 18977897969 is a prime.

It is a super-2 number, since 2×18977898481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18977898481.

It is not an unprimeable number, because it can be changed into a prime (18972898481) 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, 121471 + ... + 229588.

It is an arithmetic number, because the mean of its divisors is an integer number (4744575900).

Almost surely, 2^18977898481 is an apocalyptic number.

It is an amenable number.

18977898481 is a deficient number, since it is larger than the sum of its proper divisors (405119).

18977898481 is an equidigital number, since it uses as much as digits as its factorization.

18977898481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405118.

The product of its digits is 65028096, while the sum is 70.

The spelling of 18977898481 in words is "eighteen billion, nine hundred seventy-seven million, eight hundred ninety-eight thousand, four hundred eighty-one".