1566215473 has 4 divisors (see below), whose sum is σ = 1566563428. Its totient is φ = 1565867520.

The previous prime is 1566215459. The next prime is 1566215479. The reversal of 1566215473 is 3745126651.

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 866242624 + 699972849 = 29432^2 + 26457^2 .

It is a cyclic number.

It is not a de Polignac number, because 1566215473 - 2²⁵ = 1532661041 is a prime.

It is a super-2 number, since 2×1566215473² = 4906061815729227458, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1566215479) 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, 167136 + ... + 176257.

It is an arithmetic number, because the mean of its divisors is an integer number (391640857).

Almost surely, 2^1566215473 is an apocalyptic number.

It is an amenable number.

1566215473 is a deficient number, since it is larger than the sum of its proper divisors (347955).

1566215473 is an equidigital number, since it uses as much as digits as its factorization.

1566215473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347954.

The product of its digits is 151200, while the sum is 40.

The square root of 1566215473 is about 39575.4402755042. The cubic root of 1566215473 is about 1161.3162508825.

The spelling of 1566215473 in words is "one billion, five hundred sixty-six million, two hundred fifteen thousand, four hundred seventy-three".