19918057 has 2 divisors, whose sum is σ = 19918058. Its totient is φ = 19918056.

The previous prime is 19918049. The next prime is 19918081. The reversal of 19918057 is 75081991.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19749136 + 168921 = 4444^2 + 411^2 .

It is a cyclic number.

It is not a de Polignac number, because 19918057 - 2³ = 19918049 is a prime.

It is not a weakly prime, because it can be changed into another prime (19918007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9959028 + 9959029.

It is an arithmetic number, because the mean of its divisors is an integer number (9959029).

Almost surely, 2^19918057 is an apocalyptic number.

It is an amenable number.

19918057 is a deficient number, since it is larger than the sum of its proper divisors (1).

19918057 is an equidigital number, since it uses as much as digits as its factorization.

19918057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 40.

The square root of 19918057 is about 4462.9650457963. The cubic root of 19918057 is about 271.0705416777.

The spelling of 19918057 in words is "nineteen million, nine hundred eighteen thousand, fifty-seven".