51696621 has 12 divisors (see below), whose sum is σ = 76410048. Its totient is φ = 33662664.

The previous prime is 51696611. The next prime is 51696637. The reversal of 51696621 is 12669615.

It is not a de Polignac number, because 51696621 - 2⁹ = 51696109 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51696611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66405 + ... + 67178.

It is an arithmetic number, because the mean of its divisors is an integer number (6367504).

Almost surely, 2^51696621 is an apocalyptic number.

It is an amenable number.

51696621 is a deficient number, since it is larger than the sum of its proper divisors (24713427).

51696621 is a wasteful number, since it uses less digits than its factorization.

51696621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133632 (or 133629 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 51696621 is about 7190.0362307849. The cubic root of 51696621 is about 372.5238241297.

The spelling of 51696621 in words is "fifty-one million, six hundred ninety-six thousand, six hundred twenty-one".