51005009642 has 4 divisors (see below), whose sum is σ = 76507514466. Its totient is φ = 25502504820.

The previous prime is 51005009641. The next prime is 51005009647. The reversal of 51005009642 is 24690050015.

It is a happy number.

51005009642 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 only one way, i.e., 49523606521 + 1481403121 = 222539^2 + 38489^2 .

It is a super-2 number, since 2×51005009642² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51005009599 and 51005009608.

It is not an unprimeable number, because it can be changed into a prime (51005009641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12751252409 + ... + 12751252412.

Almost surely, 2^51005009642 is an apocalyptic number.

51005009642 is a deficient number, since it is larger than the sum of its proper divisors (25502504824).

51005009642 is a wasteful number, since it uses less digits than its factorization.

51005009642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25502504823.

The product of its (nonzero) digits is 10800, while the sum is 32.

Adding to 51005009642 its reverse (24690050015), we get a palindrome (75695059657).

The spelling of 51005009642 in words is "fifty-one billion, five million, nine thousand, six hundred forty-two".