1649609491 has 2 divisors, whose sum is σ = 1649609492. Its totient is φ = 1649609490.

The previous prime is 1649609483. The next prime is 1649609503. The reversal of 1649609491 is 1949069461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1649609491 - 2³ = 1649609483 is a prime.

It is a super-2 number, since 2×1649609491² = 5442422945594558162, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1649609411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824804745 + 824804746.

It is an arithmetic number, because the mean of its divisors is an integer number (824804746).

Almost surely, 2^1649609491 is an apocalyptic number.

1649609491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649609491 is an equidigital number, since it uses as much as digits as its factorization.

1649609491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 49.

The square root of 1649609491 is about 40615.3849052302. The cubic root of 1649609491 is about 1181.5725206656.

The spelling of 1649609491 in words is "one billion, six hundred forty-nine million, six hundred nine thousand, four hundred ninety-one".