51209198741 has 4 divisors (see below), whose sum is σ = 52175410092. Its totient is φ = 50242987392.

The previous prime is 51209198737. The next prime is 51209198759. The reversal of 51209198741 is 14789190215.

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 42326890225 + 8882308516 = 205735^2 + 94246^2 .

It is a cyclic number.

It is not a de Polignac number, because 51209198741 - 2² = 51209198737 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51209198771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 483105596 + ... + 483105701.

It is an arithmetic number, because the mean of its divisors is an integer number (13043852523).

Almost surely, 2^51209198741 is an apocalyptic number.

It is an amenable number.

51209198741 is a deficient number, since it is larger than the sum of its proper divisors (966211351).

51209198741 is an equidigital number, since it uses as much as digits as its factorization.

51209198741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966211350.

The product of its (nonzero) digits is 181440, while the sum is 47.

The spelling of 51209198741 in words is "fifty-one billion, two hundred nine million, one hundred ninety-eight thousand, seven hundred forty-one".