51697951 has 4 divisors (see below), whose sum is σ = 53945712. Its totient is φ = 49450192.

The previous prime is 51697931. The next prime is 51697963. The reversal of 51697951 is 15979615.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51697951 - 2⁷ = 51697823 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51697898 and 51697907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51697931) 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, 1123846 + ... + 1123891.

It is an arithmetic number, because the mean of its divisors is an integer number (13486428).

Almost surely, 2^51697951 is an apocalyptic number.

51697951 is a deficient number, since it is larger than the sum of its proper divisors (2247761).

51697951 is a wasteful number, since it uses less digits than its factorization.

51697951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2247760.

The product of its digits is 85050, while the sum is 43.

The square root of 51697951 is about 7190.1287192929. The cubic root of 51697951 is about 372.5270187450.

The spelling of 51697951 in words is "fifty-one million, six hundred ninety-seven thousand, nine hundred fifty-one".