19401638149 has 2 divisors, whose sum is σ = 19401638150. Its totient is φ = 19401638148.

The previous prime is 19401638129. The next prime is 19401638173. The reversal of 19401638149 is 94183610491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10326217924 + 9075420225 = 101618^2 + 95265^2 .

It is a cyclic number.

It is not a de Polignac number, because 19401638149 - 2¹³ = 19401629957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19401638099 and 19401638108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19401638119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9700819074 + 9700819075.

It is an arithmetic number, because the mean of its divisors is an integer number (9700819075).

Almost surely, 2^19401638149 is an apocalyptic number.

It is an amenable number.

19401638149 is a deficient number, since it is larger than the sum of its proper divisors (1).

19401638149 is an equidigital number, since it uses as much as digits as its factorization.

19401638149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 46.

The spelling of 19401638149 in words is "nineteen billion, four hundred one million, six hundred thirty-eight thousand, one hundred forty-nine".