1668266401 has 4 divisors (see below), whose sum is σ = 1668356272. Its totient is φ = 1668176532.

The previous prime is 1668266381. The next prime is 1668266447. The reversal of 1668266401 is 1046628661.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668266401 is a prime.

It is a super-2 number, since 2×1668266401² = 5566225569410985602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668666401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5631 + ... + 58036.

It is an arithmetic number, because the mean of its divisors is an integer number (417089068).

Almost surely, 2^1668266401 is an apocalyptic number.

It is an amenable number.

1668266401 is a deficient number, since it is larger than the sum of its proper divisors (89871).

1668266401 is an equidigital number, since it uses as much as digits as its factorization.

1668266401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89870.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 1668266401 is about 40844.4170113860. The cubic root of 1668266401 is about 1186.0103191490.

The spelling of 1668266401 in words is "one billion, six hundred sixty-eight million, two hundred sixty-six thousand, four hundred one".