254661821 has 2 divisors, whose sum is σ = 254661822. Its totient is φ = 254661820.

The previous prime is 254661817. The next prime is 254661833. The reversal of 254661821 is 128166452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168636196 + 86025625 = 12986^2 + 9275^2 .

It is a cyclic number.

It is not a de Polignac number, because 254661821 - 2² = 254661817 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (254661521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127330910 + 127330911.

It is an arithmetic number, because the mean of its divisors is an integer number (127330911).

Almost surely, 2^254661821 is an apocalyptic number.

It is an amenable number.

254661821 is a deficient number, since it is larger than the sum of its proper divisors (1).

254661821 is an equidigital number, since it uses as much as digits as its factorization.

254661821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 35.

The square root of 254661821 is about 15958.1271144204. The cubic root of 254661821 is about 633.8521193107.

The spelling of 254661821 in words is "two hundred fifty-four million, six hundred sixty-one thousand, eight hundred twenty-one".