51816949 has 4 divisors (see below), whose sum is σ = 52049536. Its totient is φ = 51584364.

The previous prime is 51816943. The next prime is 51816959. The reversal of 51816949 is 94961815.

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 51816949 - 2⁵ = 51816917 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 (51816943) 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, 115959 + ... + 116404.

It is an arithmetic number, because the mean of its divisors is an integer number (13012384).

Almost surely, 2^51816949 is an apocalyptic number.

It is an amenable number.

51816949 is a deficient number, since it is larger than the sum of its proper divisors (232587).

51816949 is a wasteful number, since it uses less digits than its factorization.

51816949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232586.

The product of its digits is 77760, while the sum is 43.

The square root of 51816949 is about 7198.3990581240. The cubic root of 51816949 is about 372.8126264589.

The spelling of 51816949 in words is "fifty-one million, eight hundred sixteen thousand, nine hundred forty-nine".