1661650355 has 4 divisors (see below), whose sum is σ = 1993980432. Its totient is φ = 1329320280.

The previous prime is 1661650273. The next prime is 1661650399. The reversal of 1661650355 is 5530561661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5530561661 = 719 ⋅7692019.

It is not a de Polignac number, because 1661650355 - 2²⁸ = 1393214899 is a prime.

It is a super-2 number, since 2×1661650355² = 5522163804543252050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166165031 + ... + 166165040.

It is an arithmetic number, because the mean of its divisors is an integer number (498495108).

Almost surely, 2^1661650355 is an apocalyptic number.

1661650355 is a deficient number, since it is larger than the sum of its proper divisors (332330077).

1661650355 is an equidigital number, since it uses as much as digits as its factorization.

1661650355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332330076.

The product of its (nonzero) digits is 81000, while the sum is 38.

The square root of 1661650355 is about 40763.3457287304. The cubic root of 1661650355 is about 1184.4404070923.

The spelling of 1661650355 in words is "one billion, six hundred sixty-one million, six hundred fifty thousand, three hundred fifty-five".