1813668149 has 4 divisors (see below), whose sum is σ = 1876208460. Its totient is φ = 1751127840.

The previous prime is 1813668127. The next prime is 1813668167. The reversal of 1813668149 is 9418663181.

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 712623025 + 1101045124 = 26695^2 + 33182^2 .

It is a cyclic number.

It is not a de Polignac number, because 1813668149 - 2⁸ = 1813667893 is a prime.

It is a super-3 number, since 3×1813668149³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1813668119) 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, 31270112 + ... + 31270169.

It is an arithmetic number, because the mean of its divisors is an integer number (469052115).

Almost surely, 2^1813668149 is an apocalyptic number.

It is an amenable number.

1813668149 is a deficient number, since it is larger than the sum of its proper divisors (62540311).

1813668149 is an equidigital number, since it uses as much as digits as its factorization.

1813668149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62540310.

The product of its digits is 248832, while the sum is 47.

The square root of 1813668149 is about 42587.1829192775. The cubic root of 1813668149 is about 1219.5116178769.

The spelling of 1813668149 in words is "one billion, eight hundred thirteen million, six hundred sixty-eight thousand, one hundred forty-nine".