18564983977 has 8 divisors (see below), whose sum is σ = 19926317736. Its totient is φ = 17233569792.

The previous prime is 18564983903. The next prime is 18564984013. The reversal of 18564983977 is 77938946581.

It can be written as a sum of positive squares in 4 ways, for example, as 7801128976 + 10763855001 = 88324^2 + 103749^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18564983977 - 2⁷ = 18564983849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18564983077) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7478608 + ... + 7481089.

It is an arithmetic number, because the mean of its divisors is an integer number (2490789717).

Almost surely, 2^18564983977 is an apocalyptic number.

18564983977 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18564983977 is a deficient number, since it is larger than the sum of its proper divisors (1361333759).

18564983977 is a wasteful number, since it uses less digits than its factorization.

18564983977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14959787.

The product of its digits is 91445760, while the sum is 67.

The spelling of 18564983977 in words is "eighteen billion, five hundred sixty-four million, nine hundred eighty-three thousand, nine hundred seventy-seven".