51261692009 has 4 divisors (see below), whose sum is σ = 55921845840. Its totient is φ = 46601538180.

The previous prime is 51261691981. The next prime is 51261692017. The reversal of 51261692009 is 90029616215.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51261692009 - 2¹² = 51261687913 is a prime.

It is a super-2 number, since 2×51261692009² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51261692309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2330076899 + ... + 2330076920.

It is an arithmetic number, because the mean of its divisors is an integer number (13980461460).

Almost surely, 2^51261692009 is an apocalyptic number.

It is an amenable number.

51261692009 is a deficient number, since it is larger than the sum of its proper divisors (4660153831).

51261692009 is a wasteful number, since it uses less digits than its factorization.

51261692009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4660153830.

The product of its (nonzero) digits is 58320, while the sum is 41.

The spelling of 51261692009 in words is "fifty-one billion, two hundred sixty-one million, six hundred ninety-two thousand, nine".