1660552221 has 4 divisors (see below), whose sum is σ = 2214069632. Its totient is φ = 1107034812.

The previous prime is 1660552217. The next prime is 1660552237. The reversal of 1660552221 is 1222550661.

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.

It is not a de Polignac number, because 1660552221 - 2² = 1660552217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660552261) 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, 276758701 + ... + 276758706.

It is an arithmetic number, because the mean of its divisors is an integer number (553517408).

Almost surely, 2^1660552221 is an apocalyptic number.

It is an amenable number.

1660552221 is a deficient number, since it is larger than the sum of its proper divisors (553517411).

1660552221 is an equidigital number, since it uses as much as digits as its factorization.

1660552221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553517410.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 1660552221 is about 40749.8738771054. The cubic root of 1660552221 is about 1184.1794294226.

The spelling of 1660552221 in words is "one billion, six hundred sixty million, five hundred fifty-two thousand, two hundred twenty-one".