51128279 has 4 divisors (see below), whose sum is σ = 51994920. Its totient is φ = 50261640.

The previous prime is 51128267. The next prime is 51128281. The reversal of 51128279 is 97282115.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51128279 is a prime.

It is a super-2 number, since 2×51128279² = 5228201827003682, which 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 (51128239) 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, 433232 + ... + 433349.

It is an arithmetic number, because the mean of its divisors is an integer number (12998730).

Almost surely, 2^51128279 is an apocalyptic number.

51128279 is a gapful number since it is divisible by the number (59) formed by its first and last digit.

51128279 is a deficient number, since it is larger than the sum of its proper divisors (866641).

51128279 is an equidigital number, since it uses as much as digits as its factorization.

51128279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866640.

The product of its digits is 10080, while the sum is 35.

The square root of 51128279 is about 7150.4041144540. The cubic root of 51128279 is about 371.1536405662.

The spelling of 51128279 in words is "fifty-one million, one hundred twenty-eight thousand, two hundred seventy-nine".