19865493025 has 27 divisors (see below), whose sum is σ = 28662077619. Its totient is φ = 13618669680.

The previous prime is 19865492981. The next prime is 19865493049. The reversal of 19865493025 is 52039456891.

The square root of 19865493025 is 140945.

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., 7151577489 + 12713915536 = 84567^2 + 112756^2 .

It is not a de Polignac number, because 19865493025 - 2¹⁷ = 19865361953 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4931062 + ... + 4935088.

Almost surely, 2^19865493025 is an apocalyptic number.

19865493025 is the 140945-th square number.

19865493025 is the 70473-rd centered octagonal number.

It is an amenable number.

19865493025 is a deficient number, since it is larger than the sum of its proper divisors (8796584594).

19865493025 is an frugal number, since it uses more digits than its factorization.

19865493025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8078 (or 4039 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 52.

The spelling of 19865493025 in words is "nineteen billion, eight hundred sixty-five million, four hundred ninety-three thousand, twenty-five".