51005500421 has 4 divisors (see below), whose sum is σ = 51343285344. Its totient is φ = 50667715500.

The previous prime is 51005500409. The next prime is 51005500423. The reversal of 51005500421 is 12400550015.

It is a happy number.

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 51005500421 - 2¹⁰ = 51005499397 is a prime.

It is a super-2 number, since 2×51005500421² (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 (51005500423) 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, 168892235 + ... + 168892536.

It is an arithmetic number, because the mean of its divisors is an integer number (12835821336).

Almost surely, 2^51005500421 is an apocalyptic number.

It is an amenable number.

51005500421 is a deficient number, since it is larger than the sum of its proper divisors (337784923).

51005500421 is a wasteful number, since it uses less digits than its factorization.

51005500421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337784922.

The product of its (nonzero) digits is 1000, while the sum is 23.

The spelling of 51005500421 in words is "fifty-one billion, five million, five hundred thousand, four hundred twenty-one".