51605397 has 8 divisors (see below), whose sum is σ = 76452480. Its totient is φ = 34403580.

The previous prime is 51605371. The next prime is 51605401. The reversal of 51605397 is 79350615.

It is a happy number.

51605397 is a `hidden beast` number, since 516 + 0 + 53 + 97 = 666.

It is not a de Polignac number, because 51605397 - 2¹⁹ = 51081109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51605317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 955629 + ... + 955682.

It is an arithmetic number, because the mean of its divisors is an integer number (9556560).

Almost surely, 2^51605397 is an apocalyptic number.

It is an amenable number.

51605397 is a deficient number, since it is larger than the sum of its proper divisors (24847083).

51605397 is a wasteful number, since it uses less digits than its factorization.

51605397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1911320 (or 1911314 counting only the distinct ones).

The product of its (nonzero) digits is 28350, while the sum is 36.

The square root of 51605397 is about 7183.6896508688. The cubic root of 51605397 is about 372.3045762615.

The spelling of 51605397 in words is "fifty-one million, six hundred five thousand, three hundred ninety-seven".