18772001 has 2 divisors, whose sum is σ = 18772002. Its totient is φ = 18772000.

The previous prime is 18771967. The next prime is 18772021. The reversal of 18772001 is 10027781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17648401 + 1123600 = 4201^2 + 1060^2 .

It is an emirp because it is prime and its reverse (10027781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18772001 - 2⁶ = 18771937 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18772021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9386000 + 9386001.

It is an arithmetic number, because the mean of its divisors is an integer number (9386001).

Almost surely, 2^18772001 is an apocalyptic number.

It is an amenable number.

18772001 is a deficient number, since it is larger than the sum of its proper divisors (1).

18772001 is an equidigital number, since it uses as much as digits as its factorization.

18772001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 18772001 is about 4332.6667307791. Note that the first 3 decimals coincide. The cubic root of 18772001 is about 265.7685107966.

Adding to 18772001 its reverse (10027781), we get a palindrome (28799782).

The spelling of 18772001 in words is "eighteen million, seven hundred seventy-two thousand, one".