1656891449 has 2 divisors, whose sum is σ = 1656891450. Its totient is φ = 1656891448.

The previous prime is 1656891433. The next prime is 1656891521. The reversal of 1656891449 is 9441986561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 940526224 + 716365225 = 30668^2 + 26765^2 .

It is a cyclic number.

It is not a de Polignac number, because 1656891449 - 2⁴ = 1656891433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1656891449.

It is not a weakly prime, because it can be changed into another prime (1656893449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828445724 + 828445725.

It is an arithmetic number, because the mean of its divisors is an integer number (828445725).

Almost surely, 2^1656891449 is an apocalyptic number.

It is an amenable number.

1656891449 is a deficient number, since it is larger than the sum of its proper divisors (1).

1656891449 is an equidigital number, since it uses as much as digits as its factorization.

1656891449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1866240, while the sum is 53.

The square root of 1656891449 is about 40704.9315071282. The cubic root of 1656891449 is about 1183.3085945411.

The spelling of 1656891449 in words is "one billion, six hundred fifty-six million, eight hundred ninety-one thousand, four hundred forty-nine".