19615963249 has 3 divisors (see below), whose sum is σ = 19616103307. Its totient is φ = 19615823192.

The previous prime is 19615963229. The next prime is 19615963267. The reversal of 19615963249 is 94236951691.

The square root of 19615963249 is 140057.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94236951691 = 239 ⋅394296869.

It can be written as a sum of positive squares in only one way, i.e., 1237280625 + 18378682624 = 35175^2 + 135568^2 .

It is not a de Polignac number, because 19615963249 - 2¹³ = 19615955057 is a prime.

It is a super-2 number, since 2×19615963249² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19615963249.

It is not an unprimeable number, because it can be changed into a prime (19615963229) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 70029 + ... + 210085.

Almost surely, 2^19615963249 is an apocalyptic number.

19615963249 is the 140057-th square number.

19615963249 is the 70029-th centered octagonal number.

It is an amenable number.

19615963249 is a deficient number, since it is larger than the sum of its proper divisors (140058).

19615963249 is an frugal number, since it uses more digits than its factorization.

19615963249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280114 (or 140057 counting only the distinct ones).

The product of its digits is 3149280, while the sum is 55.

The spelling of 19615963249 in words is "nineteen billion, six hundred fifteen million, nine hundred sixty-three thousand, two hundred forty-nine".