18969901 has 2 divisors, whose sum is σ = 18969902. Its totient is φ = 18969900.

The previous prime is 18969877. The next prime is 18969913. The reversal of 18969901 is 10996981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17023876 + 1946025 = 4126^2 + 1395^2 .

It is a cyclic number.

It is not a de Polignac number, because 18969901 - 2⁵ = 18969869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18969931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9484950 + 9484951.

It is an arithmetic number, because the mean of its divisors is an integer number (9484951).

Almost surely, 2^18969901 is an apocalyptic number.

It is an amenable number.

18969901 is a deficient number, since it is larger than the sum of its proper divisors (1).

18969901 is an equidigital number, since it uses as much as digits as its factorization.

18969901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 18969901 is about 4355.4449830069. Note that the first 3 decimals coincide. The cubic root of 18969901 is about 266.6991847498.

The spelling of 18969901 in words is "eighteen million, nine hundred sixty-nine thousand, nine hundred one".