51036783781 has 4 divisors (see below), whose sum is σ = 51083736832. Its totient is φ = 50989830732.

The previous prime is 51036783773. The next prime is 51036783793. The reversal of 51036783781 is 18738763015.

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.

It is a cyclic number.

It is not a de Polignac number, because 51036783781 - 2³ = 51036783773 is a prime.

It is a super-2 number, since 2×51036783781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51036783751) 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, 23474895 + ... + 23477068.

It is an arithmetic number, because the mean of its divisors is an integer number (12770934208).

Almost surely, 2^51036783781 is an apocalyptic number.

It is an amenable number.

51036783781 is a deficient number, since it is larger than the sum of its proper divisors (46953051).

51036783781 is a wasteful number, since it uses less digits than its factorization.

51036783781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46953050.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 51036783781 in words is "fifty-one billion, thirty-six million, seven hundred eighty-three thousand, seven hundred eighty-one".