51782015421 has 40 divisors (see below), whose sum is σ = 78521386680. Its totient is φ = 34001399808.

The previous prime is 51782015407. The next prime is 51782015429. The reversal of 51782015421 is 12451028715.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 384591321 + 51397424100 = 19611^2 + 226710^2 .

It is not a de Polignac number, because 51782015421 - 2¹⁰ = 51782014397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51782015429) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4565085 + ... + 4576413.

It is an arithmetic number, because the mean of its divisors is an integer number (1963034667).

Almost surely, 2^51782015421 is an apocalyptic number.

It is an amenable number.

51782015421 is a deficient number, since it is larger than the sum of its proper divisors (26739371259).

51782015421 is a wasteful number, since it uses less digits than its factorization.

51782015421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12187 (or 12178 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The spelling of 51782015421 in words is "fifty-one billion, seven hundred eighty-two million, fifteen thousand, four hundred twenty-one".