19504077649 has 27 divisors (see below), whose sum is σ = 23094659163. Its totient is φ = 16423663200.

The previous prime is 19504077647. The next prime is 19504077653. The reversal of 19504077649 is 94677040591.

The square root of 19504077649 is 139657.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 13180647249 + 6323430400 = 114807^2 + 79520^2 .

It is not a de Polignac number, because 19504077649 - 2¹ = 19504077647 is a prime.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19504077596 and 19504077605.

It is not an unprimeable number, because it can be changed into a prime (19504077647) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 69409389 + ... + 69409669.

Almost surely, 2^19504077649 is an apocalyptic number.

19504077649 is the 139657-th square number.

19504077649 is the 69829-th centered octagonal number.

It is an amenable number.

19504077649 is a deficient number, since it is larger than the sum of its proper divisors (3590581514).

19504077649 is an frugal number, since it uses more digits than its factorization.

19504077649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 52.

The spelling of 19504077649 in words is "nineteen billion, five hundred four million, seventy-seven thousand, six hundred forty-nine".