51689949 has 4 divisors (see below), whose sum is σ = 68919936. Its totient is φ = 34459964.

The previous prime is 51689941. The next prime is 51689969. The reversal of 51689949 is 94998615.

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 51689949 - 2³ = 51689941 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51689941) 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, 8614989 + ... + 8614994.

It is an arithmetic number, because the mean of its divisors is an integer number (17229984).

Almost surely, 2^51689949 is an apocalyptic number.

It is an amenable number.

51689949 is a deficient number, since it is larger than the sum of its proper divisors (17229987).

51689949 is a wasteful number, since it uses less digits than its factorization.

51689949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17229986.

The product of its digits is 699840, while the sum is 51.

The square root of 51689949 is about 7189.5722404048. The cubic root of 51689949 is about 372.5077973834.

The spelling of 51689949 in words is "fifty-one million, six hundred eighty-nine thousand, nine hundred forty-nine".