51155565 has 32 divisors (see below), whose sum is σ = 88369920. Its totient is φ = 25191936.

The previous prime is 51155561. The next prime is 51155579. The reversal of 51155565 is 56555115.

It is not a de Polignac number, because 51155565 - 2² = 51155561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51155561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7449 + ... + 12561.

It is an arithmetic number, because the mean of its divisors is an integer number (2761560).

Almost surely, 2^51155565 is an apocalyptic number.

It is an amenable number.

51155565 is a deficient number, since it is larger than the sum of its proper divisors (37214355).

51155565 is a wasteful number, since it uses less digits than its factorization.

51155565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5173.

The product of its digits is 18750, while the sum is 33.

The square root of 51155565 is about 7152.3118640059. The cubic root of 51155565 is about 371.2196542440.

The spelling of 51155565 in words is "fifty-one million, one hundred fifty-five thousand, five hundred sixty-five".