20125340512421 has 16 divisors (see below), whose sum is σ = 21090712048560. Its totient is φ = 19179488993280.

The previous prime is 20125340512373. The next prime is 20125340512427. The reversal of 20125340512421 is 12421504352102.

It can be written as a sum of positive squares in 8 ways, for example, as 1718786550625 + 18406553961796 = 1311025^2 + 4290286^2 .

It is a cyclic number.

It is not a de Polignac number, because 20125340512421 - 2³⁴ = 20108160643237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20125340512427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11951720 + ... + 13531233.

It is an arithmetic number, because the mean of its divisors is an integer number (1318169503035).

Almost surely, 2^{20125340512421} is an apocalyptic number.

It is an amenable number.

20125340512421 is a deficient number, since it is larger than the sum of its proper divisors (965371536139).

20125340512421 is a wasteful number, since it uses less digits than its factorization.

20125340512421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25483336.

The product of its (nonzero) digits is 19200, while the sum is 32.

Adding to 20125340512421 its reverse (12421504352102), we get a palindrome (32546844864523).

The spelling of 20125340512421 in words is "twenty trillion, one hundred twenty-five billion, three hundred forty million, five hundred twelve thousand, four hundred twenty-one".