51921732747 has 18 divisors (see below), whose sum is σ = 69621117172. Its totient is φ = 34419521024.

The previous prime is 51921732739. The next prime is 51921732761. The reversal of 51921732747 is 74723712915.

It is not a de Polignac number, because 51921732747 - 2³ = 51921732739 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51921732696 and 51921732705.

It is not an unprimeable number, because it can be changed into a prime (51921732727) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 115638379 + ... + 115638827.

Almost surely, 2^51921732747 is an apocalyptic number.

51921732747 is a deficient number, since it is larger than the sum of its proper divisors (17699384425).

51921732747 is an frugal number, since it uses more digits than its factorization.

51921732747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1487 (or 745 counting only the distinct ones).

The product of its digits is 740880, while the sum is 48.

Multiplying 51921732747 by its sum of digits (48), we get a square (2492243171856 = 1578684²).

The spelling of 51921732747 in words is "fifty-one billion, nine hundred twenty-one million, seven hundred thirty-two thousand, seven hundred forty-seven".