16491649 has 16 divisors (see below), whose sum is σ = 18013968. Its totient is φ = 15040512.

The previous prime is 16491647. The next prime is 16491653. The reversal of 16491649 is 94619461.

16491649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 651249 + 15840400 = 807^2 + 3980^2 .

It is not a de Polignac number, because 16491649 - 2¹ = 16491647 is a prime.

It is a deceptive number, since it divides R_16491648.

It is a Duffinian number.

Its product of digits (46656) is a multiple of the sum of its prime divisors (324).

It is not an unprimeable number, because it can be changed into a prime (16491647) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120309 + ... + 120445.

It is an arithmetic number, because the mean of its divisors is an integer number (1125873).

Almost surely, 2^16491649 is an apocalyptic number.

It is an amenable number.

16491649 is a deficient number, since it is larger than the sum of its proper divisors (1522319).

16491649 is a wasteful number, since it uses less digits than its factorization.

16491649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324.

The product of its digits is 46656, while the sum is 40.

The square root of 16491649 is about 4060.9911351787. The cubic root of 16491649 is about 254.5392114231.

The spelling of 16491649 in words is "sixteen million, four hundred ninety-one thousand, six hundred forty-nine".