51979399 has 4 divisors (see below), whose sum is σ = 52266760. Its totient is φ = 51692040.

The previous prime is 51979391. The next prime is 51979409. The reversal of 51979399 is 99397915.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99397915 = 5 ⋅19879583.

It is a cyclic number.

It is not a de Polignac number, because 51979399 - 2³ = 51979391 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 (51979391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143409 + ... + 143770.

It is an arithmetic number, because the mean of its divisors is an integer number (13066690).

Almost surely, 2^51979399 is an apocalyptic number.

51979399 is a deficient number, since it is larger than the sum of its proper divisors (287361).

51979399 is a wasteful number, since it uses less digits than its factorization.

51979399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287360.

The product of its digits is 688905, while the sum is 52.

The square root of 51979399 is about 7209.6739870815. The cubic root of 51979399 is about 373.2018184901.

The spelling of 51979399 in words is "fifty-one million, nine hundred seventy-nine thousand, three hundred ninety-nine".