51001001 has 2 divisors, whose sum is σ = 51001002. Its totient is φ = 51001000.

The previous prime is 51000949. The next prime is 51001009. The reversal of 51001001 is 10010015.

It is a happy number.

It is an a-pointer prime, because the next prime (51001009) can be obtained adding 51001001 to its sum of digits (8).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50069776 + 931225 = 7076^2 + 965^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51001001 is a prime.

It is a super-2 number, since 2×51001001² = 5202204206004002, which contains 22 as substring.

It is a Sophie Germain prime.

51001001 is a modest number, since divided by 1001 gives 51 as remainder.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 51001001.

It is not a weakly prime, because it can be changed into another prime (51001009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25500500 + 25500501.

It is an arithmetic number, because the mean of its divisors is an integer number (25500501).

Almost surely, 2^51001001 is an apocalyptic number.

It is an amenable number.

51001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

51001001 is an equidigital number, since it uses as much as digits as its factorization.

51001001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5, while the sum is 8.

The square root of 51001001 is about 7141.4985122172. The cubic root of 51001001 is about 370.8454031449.

Adding to 51001001 its reverse (10010015), we get a palindrome (61011016).

It can be divided in two parts, 5 and 1001001, that multiplied together give a palindrome (5005005).

The spelling of 51001001 in words is "fifty-one million, one thousand, one".