18772101 has 8 divisors (see below), whose sum is σ = 27810560. Its totient is φ = 12514716.

The previous prime is 18772099. The next prime is 18772121. The reversal of 18772101 is 10127781.

It is not a de Polignac number, because 18772101 - 2¹ = 18772099 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 695263 = 18772101 / (1 + 8 + 7 + 7 + 2 + 1 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18772121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 347605 + ... + 347658.

It is an arithmetic number, because the mean of its divisors is an integer number (3476320).

Almost surely, 2^18772101 is an apocalyptic number.

It is an amenable number.

18772101 is a deficient number, since it is larger than the sum of its proper divisors (9038459).

18772101 is an equidigital number, since it uses as much as digits as its factorization.

18772101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695272 (or 695266 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 27.

The square root of 18772101 is about 4332.6782710005. The cubic root of 18772101 is about 265.7689827194.

Adding to 18772101 its reverse (10127781), we get a palindrome (28899882).

The spelling of 18772101 in words is "eighteen million, seven hundred seventy-two thousand, one hundred one".