2051511165 has 32 divisors (see below), whose sum is σ = 3978691200. Its totient is φ = 994671360.

The previous prime is 2051511157. The next prime is 2051511173. The reversal of 2051511165 is 5611151502.

It is an interprime number because it is at equal distance from previous prime (2051511157) and next prime (2051511173).

It is not a de Polignac number, because 2051511165 - 2³ = 2051511157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 689260 + ... + 692229.

It is an arithmetic number, because the mean of its divisors is an integer number (124334100).

Almost surely, 2^2051511165 is an apocalyptic number.

It is an amenable number.

2051511165 is a deficient number, since it is larger than the sum of its proper divisors (1927180035).

2051511165 is a wasteful number, since it uses less digits than its factorization.

2051511165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381514 (or 1381508 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 27.

The square root of 2051511165 is about 45293.6106421204. The cubic root of 2051511165 is about 1270.6461599126.

Adding to 2051511165 its reverse (5611151502), we get a palindrome (7662662667).

The spelling of 2051511165 in words is "two billion, fifty-one million, five hundred eleven thousand, one hundred sixty-five".