51779421 has 12 divisors (see below), whose sum is σ = 74954880. Its totient is φ = 34444680.

The previous prime is 51779407. The next prime is 51779447. The reversal of 51779421 is 12497715.

It is a happy number.

It is not a de Polignac number, because 51779421 - 2⁷ = 51779293 is a prime.

It is a super-2 number, since 2×51779421² = 5362216878190482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51779461) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1695 + ... + 10316.

It is an arithmetic number, because the mean of its divisors is an integer number (6246240).

Almost surely, 2^51779421 is an apocalyptic number.

It is an amenable number.

51779421 is a deficient number, since it is larger than the sum of its proper divisors (23175459).

51779421 is a wasteful number, since it uses less digits than its factorization.

51779421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12496 (or 12493 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

The square root of 51779421 is about 7195.7918952677. The cubic root of 51779421 is about 372.7226025608.

The spelling of 51779421 in words is "fifty-one million, seven hundred seventy-nine thousand, four hundred twenty-one".