20523134551 has 4 divisors (see below), whose sum is σ = 20559980952. Its totient is φ = 20486288152.

The previous prime is 20523134521. The next prime is 20523134561. The reversal of 20523134551 is 15543132502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15543132502 = 2 ⋅7771566251.

It is a cyclic number.

It is not a de Polignac number, because 20523134551 - 2⁹ = 20523134039 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 (20523134501) 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, 18422365 + ... + 18423478.

It is an arithmetic number, because the mean of its divisors is an integer number (5139995238).

Almost surely, 2^20523134551 is an apocalyptic number.

20523134551 is a deficient number, since it is larger than the sum of its proper divisors (36846401).

20523134551 is an equidigital number, since it uses as much as digits as its factorization.

20523134551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36846400.

The product of its (nonzero) digits is 18000, while the sum is 31.

The spelling of 20523134551 in words is "twenty billion, five hundred twenty-three million, one hundred thirty-four thousand, five hundred fifty-one".