18681453531 has 24 divisors (see below), whose sum is σ = 29095584336. Its totient is φ = 11482217280.

The previous prime is 18681453529. The next prime is 18681453533. The reversal of 18681453531 is 13535418681.

18681453531 is a `hidden beast` number, since 1 + 8 + 6 + 81 + 4 + 535 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (18681453529) and next prime (18681453533).

It is not a de Polignac number, because 18681453531 - 2¹ = 18681453529 is a prime.

It is a super-2 number, since 2×18681453531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18681453533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1185 + ... + 193298.

It is an arithmetic number, because the mean of its divisors is an integer number (1212316014).

Almost surely, 2^18681453531 is an apocalyptic number.

18681453531 is a deficient number, since it is larger than the sum of its proper divisors (10414130805).

18681453531 is a wasteful number, since it uses less digits than its factorization.

18681453531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195323 (or 195320 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The spelling of 18681453531 in words is "eighteen billion, six hundred eighty-one million, four hundred fifty-three thousand, five hundred thirty-one".