51217253421 has 16 divisors (see below), whose sum is σ = 72317847168. Its totient is φ = 32131366400.

The previous prime is 51217253407. The next prime is 51217253447. The reversal of 51217253421 is 12435271215.

It is a happy number.

51217253421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 51217253421 - 2⁵ = 51217253389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51217253471) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 272401 + ... + 420281.

It is an arithmetic number, because the mean of its divisors is an integer number (4519865448).

Almost surely, 2^51217253421 is an apocalyptic number.

51217253421 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51217253421 is a deficient number, since it is larger than the sum of its proper divisors (21100593747).

51217253421 is a wasteful number, since it uses less digits than its factorization.

51217253421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154692.

The product of its digits is 16800, while the sum is 33.

The spelling of 51217253421 in words is "fifty-one billion, two hundred seventeen million, two hundred fifty-three thousand, four hundred twenty-one".