2551961 has 2 divisors, whose sum is σ = 2551962. Its totient is φ = 2551960.

The previous prime is 2551957. The next prime is 2551979. The reversal of 2551961 is 1691552.

2551961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1308736 + 1243225 = 1144^2 + 1115^2 .

It is a cyclic number.

It is not a de Polignac number, because 2551961 - 2² = 2551957 is a prime.

It is not a weakly prime, because it can be changed into another prime (2551981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1275980 + 1275981.

It is an arithmetic number, because the mean of its divisors is an integer number (1275981).

2^2551961 is an apocalyptic number.

It is an amenable number.

2551961 is a deficient number, since it is larger than the sum of its proper divisors (1).

2551961 is an equidigital number, since it uses as much as digits as its factorization.

2551961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 29.

The square root of 2551961 is about 1597.4858371829. The cubic root of 2551961 is about 136.6547329126.

The spelling of 2551961 in words is "two million, five hundred fifty-one thousand, nine hundred sixty-one".