51155397 has 12 divisors (see below), whose sum is σ = 78237900. Its totient is φ = 32097408.

The previous prime is 51155387. The next prime is 51155443. The reversal of 51155397 is 79355115.

51155397 is a `hidden beast` number, since 5 + 11 + 553 + 97 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 24591681 + 26563716 = 4959^2 + 5154^2 .

It is not a de Polignac number, because 51155397 - 2¹⁹ = 50631109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51155347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 167022 + ... + 167327.

It is an arithmetic number, because the mean of its divisors is an integer number (6519825).

Almost surely, 2^51155397 is an apocalyptic number.

It is an amenable number.

51155397 is a deficient number, since it is larger than the sum of its proper divisors (27082503).

51155397 is a wasteful number, since it uses less digits than its factorization.

51155397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334372 (or 334369 counting only the distinct ones).

The product of its digits is 23625, while the sum is 36.

The square root of 51155397 is about 7152.3001195420. The cubic root of 51155397 is about 371.2192478694.

The spelling of 51155397 in words is "fifty-one million, one hundred fifty-five thousand, three hundred ninety-seven".