51666501 has 4 divisors (see below), whose sum is σ = 68888672. Its totient is φ = 34444332.

The previous prime is 51666499. The next prime is 51666539. The reversal of 51666501 is 10566615.

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 not a de Polignac number, because 51666501 - 2¹ = 51666499 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 (51666001) 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, 8611081 + ... + 8611086.

It is an arithmetic number, because the mean of its divisors is an integer number (17222168).

Almost surely, 2^51666501 is an apocalyptic number.

It is an amenable number.

51666501 is a deficient number, since it is larger than the sum of its proper divisors (17222171).

51666501 is a wasteful number, since it uses less digits than its factorization.

51666501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17222170.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 51666501 is about 7187.9413603618. The cubic root of 51666501 is about 372.4514622281.

The spelling of 51666501 in words is "fifty-one million, six hundred sixty-six thousand, five hundred one".