663790261 has 2 divisors, whose sum is σ = 663790262. Its totient is φ = 663790260.

The previous prime is 663790223. The next prime is 663790273. The reversal of 663790261 is 162097366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 575712036 + 88078225 = 23994^2 + 9385^2 .

It is a cyclic number.

It is not a de Polignac number, because 663790261 - 2⁷ = 663790133 is a prime.

It is a super-3 number, since 3×663790261³ (a number of 27 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663790291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331895130 + 331895131.

It is an arithmetic number, because the mean of its divisors is an integer number (331895131).

Almost surely, 2^663790261 is an apocalyptic number.

It is an amenable number.

663790261 is a deficient number, since it is larger than the sum of its proper divisors (1).

663790261 is an equidigital number, since it uses as much as digits as its factorization.

663790261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 40.

The square root of 663790261 is about 25764.1274061436. The cubic root of 663790261 is about 872.3222675553.

The spelling of 663790261 in words is "six hundred sixty-three million, seven hundred ninety thousand, two hundred sixty-one".