51637797949 has 4 divisors (see below), whose sum is σ = 51640480864. Its totient is φ = 51635115036.

The previous prime is 51637797947. The next prime is 51637797971. The reversal of 51637797949 is 94979773615.

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 51637797949 - 2¹ = 51637797947 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 (51637797943) 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, 1312377 + ... + 1351150.

It is an arithmetic number, because the mean of its divisors is an integer number (12910120216).

Almost surely, 2^51637797949 is an apocalyptic number.

It is an amenable number.

51637797949 is a deficient number, since it is larger than the sum of its proper divisors (2682915).

51637797949 is a wasteful number, since it uses less digits than its factorization.

51637797949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2682914.

The product of its digits is 90016920, while the sum is 67.

The spelling of 51637797949 in words is "fifty-one billion, six hundred thirty-seven million, seven hundred ninety-seven thousand, nine hundred forty-nine".