20625255161 has 4 divisors (see below), whose sum is σ = 23571720192. Its totient is φ = 17678790132.

The previous prime is 20625255137. The next prime is 20625255169. The reversal of 20625255161 is 16155252602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16155252602 = 2 ⋅8077626301.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20625255161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20625255169) 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, 1473232505 + ... + 1473232518.

It is an arithmetic number, because the mean of its divisors is an integer number (5892930048).

Almost surely, 2^20625255161 is an apocalyptic number.

It is an amenable number.

20625255161 is a deficient number, since it is larger than the sum of its proper divisors (2946465031).

20625255161 is an equidigital number, since it uses as much as digits as its factorization.

20625255161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2946465030.

The product of its (nonzero) digits is 36000, while the sum is 35.

The spelling of 20625255161 in words is "twenty billion, six hundred twenty-five million, two hundred fifty-five thousand, one hundred sixty-one".