1666260401 has 12 divisors (see below), whose sum is σ = 1806260508. Its totient is φ = 1536410304.

The previous prime is 1666260397. The next prime is 1666260467. The reversal of 1666260401 is 1040626661.

It can be written as a sum of positive squares in 6 ways, for example, as 458002801 + 1208257600 = 21401^2 + 34760^2 .

It is not a de Polignac number, because 1666260401 - 2² = 1666260397 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666260601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 166331 + ... + 176063.

It is an arithmetic number, because the mean of its divisors is an integer number (150521709).

Almost surely, 2^1666260401 is an apocalyptic number.

It is an amenable number.

1666260401 is a deficient number, since it is larger than the sum of its proper divisors (140000107).

1666260401 is a wasteful number, since it uses less digits than its factorization.

1666260401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10772 (or 10759 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 1666260401 is about 40819.8530252131. The cubic root of 1666260401 is about 1185.5347574260.

It can be divided in two parts, 1666260 and 401, that added together give a palindrome (1666661).

The spelling of 1666260401 in words is "one billion, six hundred sixty-six million, two hundred sixty thousand, four hundred one".