1445666399 has 4 divisors (see below), whose sum is σ = 1447655664. Its totient is φ = 1443677136.

The previous prime is 1445666347. The next prime is 1445666401. The reversal of 1445666399 is 9936665441.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1445666399 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 1445666399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1445666329) 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, 993542 + ... + 994995.

It is an arithmetic number, because the mean of its divisors is an integer number (361913916).

Almost surely, 2^1445666399 is an apocalyptic number.

1445666399 is a deficient number, since it is larger than the sum of its proper divisors (1989265).

1445666399 is an equidigital number, since it uses as much as digits as its factorization.

1445666399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1989264.

The product of its digits is 4199040, while the sum is 53.

The square root of 1445666399 is about 38021.9199804534. The cubic root of 1445666399 is about 1130.7224865136.

The spelling of 1445666399 in words is "one billion, four hundred forty-five million, six hundred sixty-six thousand, three hundred ninety-nine".