1662566401 has 4 divisors (see below), whose sum is σ = 1677279492. Its totient is φ = 1647853312.

The previous prime is 1662566393. The next prime is 1662566429. The reversal of 1662566401 is 1046652661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1046652661 = 1789 ⋅585049.

It can be written as a sum of positive squares in 2 ways, for example, as 184932801 + 1477633600 = 13599^2 + 38440^2 .

It is a cyclic number.

It is not a de Polignac number, because 1662566401 - 2³ = 1662566393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1662561401) 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, 7356376 + ... + 7356601.

It is an arithmetic number, because the mean of its divisors is an integer number (419319873).

Almost surely, 2^1662566401 is an apocalyptic number.

It is an amenable number.

1662566401 is a deficient number, since it is larger than the sum of its proper divisors (14713091).

1662566401 is a wasteful number, since it uses less digits than its factorization.

1662566401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14713090.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 1662566401 is about 40774.5803289255. The cubic root of 1662566401 is about 1184.6580225837.

The spelling of 1662566401 in words is "one billion, six hundred sixty-two million, five hundred sixty-six thousand, four hundred one".