1649857043 has 4 divisors (see below), whose sum is σ = 1650442248. Its totient is φ = 1649271840.

The previous prime is 1649857019. The next prime is 1649857049. The reversal of 1649857043 is 3407589461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3407589461 = 27743 ⋅122827.

It is a cyclic number.

It is not a de Polignac number, because 1649857043 - 2⁸ = 1649856787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1649857049) 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, 288353 + ... + 294018.

It is an arithmetic number, because the mean of its divisors is an integer number (412610562).

Almost surely, 2^1649857043 is an apocalyptic number.

1649857043 is a deficient number, since it is larger than the sum of its proper divisors (585205).

1649857043 is an equidigital number, since it uses as much as digits as its factorization.

1649857043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 585204.

The product of its (nonzero) digits is 725760, while the sum is 47.

The square root of 1649857043 is about 40618.4323060356. The cubic root of 1649857043 is about 1181.6316227363.

The spelling of 1649857043 in words is "one billion, six hundred forty-nine million, eight hundred fifty-seven thousand, forty-three".