2561500001 has 2 divisors, whose sum is σ = 2561500002. Its totient is φ = 2561500000.

The previous prime is 2561499989. The next prime is 2561500003. The reversal of 2561500001 is 1000051652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2480139601 + 81360400 = 49801^2 + 9020^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561500001 - 2⁶ = 2561499937 is a prime.

It is a super-2 number, since 2×2561500001² = 13122564510246000002, which contains 22 as substring.

Together with 2561500003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2561500003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280750000 + 1280750001.

It is an arithmetic number, because the mean of its divisors is an integer number (1280750001).

Almost surely, 2^2561500001 is an apocalyptic number.

It is an amenable number.

2561500001 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561500001 is an equidigital number, since it uses as much as digits as its factorization.

2561500001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 2561500001 is about 50611.2635783775. The cubic root of 2561500001 is about 1368.2478890937.

Adding to 2561500001 its reverse (1000051652), we get a palindrome (3561551653).

The spelling of 2561500001 in words is "two billion, five hundred sixty-one million, five hundred thousand, one".