1640550266 has 4 divisors (see below), whose sum is σ = 2460825402. Its totient is φ = 820275132.

The previous prime is 1640550257. The next prime is 1640550277. The reversal of 1640550266 is 6620550461.

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

It can be written as a sum of positive squares in only one way, i.e., 1313700025 + 326850241 = 36245^2 + 18079^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410137565 + ... + 410137568.

Almost surely, 2^1640550266 is an apocalyptic number.

1640550266 is a deficient number, since it is larger than the sum of its proper divisors (820275136).

1640550266 is an equidigital number, since it uses as much as digits as its factorization.

1640550266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820275135.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 1640550266 is about 40503.7068180185. The cubic root of 1640550266 is about 1179.4055863809.

The spelling of 1640550266 in words is "one billion, six hundred forty million, five hundred fifty thousand, two hundred sixty-six".