1820148709 has 4 divisors (see below), whose sum is σ = 1833434604. Its totient is φ = 1806862816.

The previous prime is 1820148697. The next prime is 1820148727. The reversal of 1820148709 is 9078410281.

It is a happy number.

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 415548225 + 1404600484 = 20385^2 + 37478^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820148709 - 2⁷ = 1820148581 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 (1820148739) 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, 6642742 + ... + 6643015.

It is an arithmetic number, because the mean of its divisors is an integer number (458358651).

Almost surely, 2^1820148709 is an apocalyptic number.

It is an amenable number.

1820148709 is a deficient number, since it is larger than the sum of its proper divisors (13285895).

1820148709 is a wasteful number, since it uses less digits than its factorization.

1820148709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13285894.

The product of its (nonzero) digits is 32256, while the sum is 40.

The square root of 1820148709 is about 42663.2008761649. The cubic root of 1820148709 is about 1220.9624021659.

The spelling of 1820148709 in words is "one billion, eight hundred twenty million, one hundred forty-eight thousand, seven hundred nine".