51309965 has 32 divisors (see below), whose sum is σ = 72923136. Its totient is φ = 33929280.

The previous prime is 51309959. The next prime is 51309971. The reversal of 51309965 is 56990315.

It is an interprime number because it is at equal distance from previous prime (51309959) and next prime (51309971).

It is not a de Polignac number, because 51309965 - 2²⁰ = 50261389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 154850 + ... + 155180.

It is an arithmetic number, because the mean of its divisors is an integer number (2278848).

Almost surely, 2^51309965 is an apocalyptic number.

It is an amenable number.

51309965 is a deficient number, since it is larger than the sum of its proper divisors (21613171).

51309965 is a wasteful number, since it uses less digits than its factorization.

51309965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489.

The product of its (nonzero) digits is 36450, while the sum is 38.

The square root of 51309965 is about 7163.0974445417. The cubic root of 51309965 is about 371.5927563443.

The spelling of 51309965 in words is "fifty-one million, three hundred nine thousand, nine hundred sixty-five".