2154004561 has 2 divisors, whose sum is σ = 2154004562. Its totient is φ = 2154004560.

The previous prime is 2154004471. The next prime is 2154004571. The reversal of 2154004561 is 1654004512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2150084161 + 3920400 = 46369^2 + 1980^2 .

It is a cyclic number.

It is not a de Polignac number, because 2154004561 - 2²¹ = 2151907409 is a prime.

It is not a weakly prime, because it can be changed into another prime (2154004571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077002280 + 1077002281.

It is an arithmetic number, because the mean of its divisors is an integer number (1077002281).

Almost surely, 2^2154004561 is an apocalyptic number.

It is an amenable number.

2154004561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2154004561 is an equidigital number, since it uses as much as digits as its factorization.

2154004561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 2154004561 is about 46411.2546803036. The cubic root of 2154004561 is about 1291.4637074341.

It can be divided in two parts, 215400 and 4561, that added together give a square (219961 = 469²).

The spelling of 2154004561 in words is "two billion, one hundred fifty-four million, four thousand, five hundred sixty-one".