18727890645 has 32 divisors (see below), whose sum is σ = 32913100800. Its totient is φ = 9051096384.

The previous prime is 18727890641. The next prime is 18727890689. The reversal of 18727890645 is 54609872781.

It is not a de Polignac number, because 18727890645 - 2² = 18727890641 is a prime.

It is a super-2 number, since 2×18727890645² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18727890641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1421965 + ... + 1435074.

It is an arithmetic number, because the mean of its divisors is an integer number (1028534400).

Almost surely, 2^18727890645 is an apocalyptic number.

18727890645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18727890645 is a deficient number, since it is larger than the sum of its proper divisors (14185210155).

18727890645 is a wasteful number, since it uses less digits than its factorization.

18727890645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2857089.

The product of its (nonzero) digits is 6773760, while the sum is 57.

The spelling of 18727890645 in words is "eighteen billion, seven hundred twenty-seven million, eight hundred ninety thousand, six hundred forty-five".