51215445421 has 16 divisors (see below), whose sum is σ = 61625347200. Its totient is φ = 41579854848.

The previous prime is 51215445409. The next prime is 51215445499. The reversal of 51215445421 is 12454451215.

It is not a de Polignac number, because 51215445421 - 2²⁷ = 51081227693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51215445521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 647985 + ... + 722713.

It is an arithmetic number, because the mean of its divisors is an integer number (3851584200).

Almost surely, 2^51215445421 is an apocalyptic number.

It is an amenable number.

51215445421 is a deficient number, since it is larger than the sum of its proper divisors (10409901779).

51215445421 is a wasteful number, since it uses less digits than its factorization.

51215445421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79908.

The product of its digits is 32000, while the sum is 34.

Adding to 51215445421 its reverse (12454451215), we get a palindrome (63669896636).

The spelling of 51215445421 in words is "fifty-one billion, two hundred fifteen million, four hundred forty-five thousand, four hundred twenty-one".