51129949 has 4 divisors (see below), whose sum is σ = 55063036. Its totient is φ = 47196864.

The previous prime is 51129913. The next prime is 51129973. The reversal of 51129949 is 94992115.

51129949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 34727449 + 16402500 = 5893^2 + 4050^2 .

It is not a de Polignac number, because 51129949 - 2¹⁵ = 51097181 is a prime.

It is a super-2 number, since 2×51129949² = 5228543369485202, 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 (51129979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1966524 + ... + 1966549.

It is an arithmetic number, because the mean of its divisors is an integer number (13765759).

Almost surely, 2^51129949 is an apocalyptic number.

It is an amenable number.

51129949 is a deficient number, since it is larger than the sum of its proper divisors (3933087).

51129949 is a wasteful number, since it uses less digits than its factorization.

51129949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3933086.

The product of its digits is 29160, while the sum is 40.

The square root of 51129949 is about 7150.5208901170. The cubic root of 51129949 is about 371.1576815122.

The spelling of 51129949 in words is "fifty-one million, one hundred twenty-nine thousand, nine hundred forty-nine".