4005649 has 2 divisors, whose sum is σ = 4005650. Its totient is φ = 4005648.

The previous prime is 4005643. The next prime is 4005653. The reversal of 4005649 is 9465004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3775249 + 230400 = 1943^2 + 480^2 .

It is a cyclic number.

It is not a de Polignac number, because 4005649 - 2⁹ = 4005137 is a prime.

It is a super-2 number, since 2×4005649² = 32090447822402, which contains 22 as substring.

4005649 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (4005643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2002824 + 2002825.

It is an arithmetic number, because the mean of its divisors is an integer number (2002825).

Almost surely, 2^4005649 is an apocalyptic number.

It is an amenable number.

4005649 is a deficient number, since it is larger than the sum of its proper divisors (1).

4005649 is an equidigital number, since it uses as much as digits as its factorization.

4005649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 4005649 is about 2001.4117517393. The cubic root of 4005649 is about 158.8147969512.

The spelling of 4005649 in words is "four million, five thousand, six hundred forty-nine".