668977261 has 4 divisors (see below), whose sum is σ = 677037312. Its totient is φ = 660917212.

The previous prime is 668977259. The next prime is 668977313. The reversal of 668977261 is 162779866.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 668977261 - 2¹ = 668977259 is a prime.

It is a super-3 number, since 3×668977261³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668977199 and 668977208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668977201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4029901 + ... + 4030066.

It is an arithmetic number, because the mean of its divisors is an integer number (169259328).

Almost surely, 2^668977261 is an apocalyptic number.

It is an amenable number.

668977261 is a deficient number, since it is larger than the sum of its proper divisors (8060051).

668977261 is an equidigital number, since it uses as much as digits as its factorization.

668977261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8060050.

The product of its digits is 1524096, while the sum is 52.

The square root of 668977261 is about 25864.5947387544. The cubic root of 668977261 is about 874.5885460340.

The spelling of 668977261 in words is "six hundred sixty-eight million, nine hundred seventy-seven thousand, two hundred sixty-one".