19775390625 has 65 divisors (see below), whose sum is σ = 36926269501. Its totient is φ = 10546875000.

The previous prime is 19775390623. The next prime is 19775390651. The reversal of 19775390625 is 52609357791.

The square root of 19775390625 is 140625.

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

19775390625 is a `hidden beast` number, since 1 + 9 + 7 + 7 + 5 + 3 + 9 + 0 + 625 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 11188773729 + 8586616896 = 105777^2 + 92664^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=3, B=1875.

It is not a de Polignac number, because 19775390625 - 2¹ = 19775390623 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 5.

It is not an unprimeable number, because it can be changed into a prime (19775390623) by changing a digit.

It is a polite number, since it can be written in 64 ways as a sum of consecutive naturals, for example, 3955078123 + ... + 3955078127.

Almost surely, 2^19775390625 is an apocalyptic number.

19775390625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19775390625 is the 140625-th square number.

19775390625 is the 70313-rd centered octagonal number.

It is an amenable number.

19775390625 is a deficient number, since it is larger than the sum of its proper divisors (17150878876).

19775390625 is an frugal number, since it uses more digits than its factorization.

19775390625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 8 counting only the distinct ones).

The product of its (nonzero) digits is 3572100, while the sum is 54.

The spelling of 19775390625 in words is "nineteen billion, seven hundred seventy-five million, three hundred ninety thousand, six hundred twenty-five".