51511001 has 4 divisors (see below), whose sum is σ = 51602100. Its totient is φ = 51419904.

The previous prime is 51510959. The next prime is 51511039. The reversal of 51511001 is 10011515.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10011515 = 5 ⋅2002303.

It can be written as a sum of positive squares in 2 ways, for example, as 32501401 + 19009600 = 5701^2 + 4360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51511001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51511051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44696 + ... + 45833.

It is an arithmetic number, because the mean of its divisors is an integer number (12900525).

Almost surely, 2^51511001 is an apocalyptic number.

It is an amenable number.

51511001 is a deficient number, since it is larger than the sum of its proper divisors (91099).

51511001 is an equidigital number, since it uses as much as digits as its factorization.

51511001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91098.

The product of its (nonzero) digits is 25, while the sum is 14.

The square root of 51511001 is about 7177.1164822650. The cubic root of 51511001 is about 372.0774326228.

Adding to 51511001 its reverse (10011515), we get a palindrome (61522516).

The spelling of 51511001 in words is "fifty-one million, five hundred eleven thousand, one".