20125644247553 has 8 divisors (see below), whose sum is σ = 21680679847848. Its totient is φ = 18571595664384.

The previous prime is 20125644247529. The next prime is 20125644247561. The reversal of 20125644247553 is 35574244652102.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1290148407409 + 18835495840144 = 1135847^2 + 4339988^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20125644247553 - 2²⁰ = 20125643198977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20125644246553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246711926 + ... + 246793487.

It is an arithmetic number, because the mean of its divisors is an integer number (2710084980981).

Almost surely, 2^{20125644247553} is an apocalyptic number.

It is an amenable number.

20125644247553 is a deficient number, since it is larger than the sum of its proper divisors (1555035600295).

20125644247553 is a wasteful number, since it uses less digits than its factorization.

20125644247553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493508563.

The product of its (nonzero) digits is 8064000, while the sum is 50.

Adding to 20125644247553 its reverse (35574244652102), we get a palindrome (55699888899655).

The spelling of 20125644247553 in words is "twenty trillion, one hundred twenty-five billion, six hundred forty-four million, two hundred forty-seven thousand, five hundred fifty-three".