51385997 has 16 divisors (see below), whose sum is σ = 57071280. Its totient is φ = 45964800.

The previous prime is 51385987. The next prime is 51386011. The reversal of 51385997 is 79958315.

It can be written as a sum of positive squares in 8 ways, for example, as 15217801 + 36168196 = 3901^2 + 6014^2 .

It is a cyclic number.

It is not a de Polignac number, because 51385997 - 2⁴ = 51385981 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51385907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121847 + ... + 122267.

It is an arithmetic number, because the mean of its divisors is an integer number (3566955).

Almost surely, 2^51385997 is an apocalyptic number.

It is an amenable number.

51385997 is a deficient number, since it is larger than the sum of its proper divisors (5685283).

51385997 is a wasteful number, since it uses less digits than its factorization.

51385997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704.

The product of its digits is 340200, while the sum is 47.

The square root of 51385997 is about 7168.4026812115. The cubic root of 51385997 is about 371.7762099658.

The spelling of 51385997 in words is "fifty-one million, three hundred eighty-five thousand, nine hundred ninety-seven".