51515115242 has 4 divisors (see below), whose sum is σ = 77272672866. Its totient is φ = 25757557620.

The previous prime is 51515115217. The next prime is 51515115247. The reversal of 51515115242 is 24251151515.

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., 37110554881 + 14404560361 = 192641^2 + 120019^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51515115199 and 51515115208.

It is not an unprimeable number, because it can be changed into a prime (51515115247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12878778809 + ... + 12878778812.

Almost surely, 2^51515115242 is an apocalyptic number.

51515115242 is a deficient number, since it is larger than the sum of its proper divisors (25757557624).

51515115242 is a wasteful number, since it uses less digits than its factorization.

51515115242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25757557623.

The product of its digits is 10000, while the sum is 32.

Adding to 51515115242 its reverse (24251151515), we get a palindrome (75766266757).

The spelling of 51515115242 in words is "fifty-one billion, five hundred fifteen million, one hundred fifteen thousand, two hundred forty-two".