1666415573 has 4 divisors (see below), whose sum is σ = 1738868448. Its totient is φ = 1593962700.

The previous prime is 1666415563. The next prime is 1666415581. The reversal of 1666415573 is 3755146661.

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 an emirpimes, since its reverse is a distinct semiprime: 3755146661 = 7 ⋅536449523.

It is a cyclic number.

It is not a de Polignac number, because 1666415573 - 2¹⁸ = 1666153429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666415563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36226403 + ... + 36226448.

It is an arithmetic number, because the mean of its divisors is an integer number (434717112).

Almost surely, 2^1666415573 is an apocalyptic number.

It is an amenable number.

1666415573 is a deficient number, since it is larger than the sum of its proper divisors (72452875).

1666415573 is an equidigital number, since it uses as much as digits as its factorization.

1666415573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72452874.

The product of its digits is 453600, while the sum is 44.

The square root of 1666415573 is about 40821.7536737461. The cubic root of 1666415573 is about 1185.5715576143.

The spelling of 1666415573 in words is "one billion, six hundred sixty-six million, four hundred fifteen thousand, five hundred seventy-three".