51645543451 has 4 divisors (see below), whose sum is σ = 52177971832. Its totient is φ = 51113115072.

The previous prime is 51645543449. The next prime is 51645543487. The reversal of 51645543451 is 15434554615.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51645543451 - 2¹ = 51645543449 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51645543398 and 51645543407.

It is not an unprimeable number, because it can be changed into a prime (51645543421) 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, 266214045 + ... + 266214238.

It is an arithmetic number, because the mean of its divisors is an integer number (13044492958).

Almost surely, 2^51645543451 is an apocalyptic number.

51645543451 is a deficient number, since it is larger than the sum of its proper divisors (532428381).

51645543451 is an equidigital number, since it uses as much as digits as its factorization.

51645543451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532428380.

The product of its digits is 720000, while the sum is 43.

The spelling of 51645543451 in words is "fifty-one billion, six hundred forty-five million, five hundred forty-three thousand, four hundred fifty-one".