51309642 has 32 divisors (see below), whose sum is σ = 110782080. Its totient is φ = 15794240.

The previous prime is 51309637. The next prime is 51309647. The reversal of 51309642 is 24690315.

51309642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (51309637) and next prime (51309647).

It is not an unprimeable number, because it can be changed into a prime (51309647) 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 15 ways as a sum of consecutive naturals, for example, 2409 + ... + 10412.

It is an arithmetic number, because the mean of its divisors is an integer number (3461940).

Almost surely, 2^51309642 is an apocalyptic number.

51309642 is an abundant number, since it is smaller than the sum of its proper divisors (59472438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51309642 is a wasteful number, since it uses less digits than its factorization.

51309642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12878.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 51309642 is about 7163.0748983938. The cubic root of 51309642 is about 371.5919766081.

Adding to 51309642 its reverse (24690315), we get a palindrome (75999957).

The spelling of 51309642 in words is "fifty-one million, three hundred nine thousand, six hundred forty-two".