20365121461 has 4 divisors (see below), whose sum is σ = 20372394924. Its totient is φ = 20357848000.

The previous prime is 20365121437. The next prime is 20365121467. The reversal of 20365121461 is 16412156302.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16412156302 = 2 ⋅8206078151.

It can be written as a sum of positive squares in 2 ways, for example, as 10344110436 + 10021011025 = 101706^2 + 100105^2 .

It is a cyclic number.

It is not a de Polignac number, because 20365121461 - 2¹³ = 20365113269 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 (20365121467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3632530 + ... + 3638131.

It is an arithmetic number, because the mean of its divisors is an integer number (5093098731).

Almost surely, 2^20365121461 is an apocalyptic number.

It is an amenable number.

20365121461 is a deficient number, since it is larger than the sum of its proper divisors (7273463).

20365121461 is an equidigital number, since it uses as much as digits as its factorization.

20365121461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7273462.

The product of its (nonzero) digits is 8640, while the sum is 31.

Adding to 20365121461 its reverse (16412156302), we get a palindrome (36777277763).

The spelling of 20365121461 in words is "twenty billion, three hundred sixty-five million, one hundred twenty-one thousand, four hundred sixty-one".