1664600401 has 4 divisors (see below), whose sum is σ = 1679331492. Its totient is φ = 1649869312.

The previous prime is 1664600383. The next prime is 1664600411. The reversal of 1664600401 is 1040064661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16321600 + 1648278801 = 4040^2 + 40599^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664600401 - 2²⁹ = 1127729489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664600401.

It is not an unprimeable number, because it can be changed into a prime (1664600411) 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, 7365376 + ... + 7365601.

It is an arithmetic number, because the mean of its divisors is an integer number (419832873).

Almost surely, 2^1664600401 is an apocalyptic number.

It is an amenable number.

1664600401 is a deficient number, since it is larger than the sum of its proper divisors (14731091).

1664600401 is a wasteful number, since it uses less digits than its factorization.

1664600401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14731090.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1664600401 is about 40799.5147152512. The cubic root of 1664600401 is about 1185.1409331096.

The spelling of 1664600401 in words is "one billion, six hundred sixty-four million, six hundred thousand, four hundred one".