18979901 has 2 divisors, whose sum is σ = 18979902. Its totient is φ = 18979900.

The previous prime is 18979817. The next prime is 18979931. The reversal of 18979901 is 10997981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13912900 + 5067001 = 3730^2 + 2251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18979901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18979931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9489950 + 9489951.

It is an arithmetic number, because the mean of its divisors is an integer number (9489951).

Almost surely, 2^18979901 is an apocalyptic number.

It is an amenable number.

18979901 is a deficient number, since it is larger than the sum of its proper divisors (1).

18979901 is an equidigital number, since it uses as much as digits as its factorization.

18979901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 18979901 is about 4356.5928200831. The cubic root of 18979901 is about 266.7460400874.

The spelling of 18979901 in words is "eighteen million, nine hundred seventy-nine thousand, nine hundred one".