19916449837 has 2 divisors, whose sum is σ = 19916449838. Its totient is φ = 19916449836.

The previous prime is 19916449831. The next prime is 19916449921. The reversal of 19916449837 is 73894461991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19848864996 + 67584841 = 140886^2 + 8221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19916449837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19916449831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9958224918 + 9958224919.

It is an arithmetic number, because the mean of its divisors is an integer number (9958224919).

Almost surely, 2^19916449837 is an apocalyptic number.

It is an amenable number.

19916449837 is a deficient number, since it is larger than the sum of its proper divisors (1).

19916449837 is an equidigital number, since it uses as much as digits as its factorization.

19916449837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11757312, while the sum is 61.

It can be divided in two parts, 199164 and 49837, that added together give a square (249001 = 499²).

The spelling of 19916449837 in words is "nineteen billion, nine hundred sixteen million, four hundred forty-nine thousand, eight hundred thirty-seven".