18881607845 has 8 divisors (see below), whose sum is σ = 22775329176. Its totient is φ = 15027019776.

The previous prime is 18881607817. The next prime is 18881607851. The reversal of 18881607845 is 54870618881.

It can be written as a sum of positive squares in 4 ways, for example, as 649587169 + 18232020676 = 25487^2 + 135026^2 .

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 18881607845 - 2¹² = 18881603749 is a prime.

It is a super-2 number, since 2×18881607845² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9782252 + ... + 9784181.

It is an arithmetic number, because the mean of its divisors is an integer number (2846916147).

Almost surely, 2^18881607845 is an apocalyptic number.

It is an amenable number.

18881607845 is a deficient number, since it is larger than the sum of its proper divisors (3893721331).

18881607845 is a wasteful number, since it uses less digits than its factorization.

18881607845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19566631.

The product of its (nonzero) digits is 3440640, while the sum is 56.

The spelling of 18881607845 in words is "eighteen billion, eight hundred eighty-one million, six hundred seven thousand, eight hundred forty-five".