51250665021 has 4 divisors (see below), whose sum is σ = 68334220032. Its totient is φ = 34167110012.

The previous prime is 51250664989. The next prime is 51250665071. The reversal of 51250665021 is 12056605215.

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 51250665021 - 2⁵ = 51250664989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51250665071) 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, 8541777501 + ... + 8541777506.

It is an arithmetic number, because the mean of its divisors is an integer number (17083555008).

Almost surely, 2^51250665021 is an apocalyptic number.

It is an amenable number.

51250665021 is a deficient number, since it is larger than the sum of its proper divisors (17083555011).

51250665021 is a wasteful number, since it uses less digits than its factorization.

51250665021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17083555010.

The product of its (nonzero) digits is 18000, while the sum is 33.

The spelling of 51250665021 in words is "fifty-one billion, two hundred fifty million, six hundred sixty-five thousand, twenty-one".