640497449 has 8 divisors (see below), whose sum is σ = 661291008. Its totient is φ = 619950240.

The previous prime is 640497437. The next prime is 640497469. The reversal of 640497449 is 944794046.

640497449 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640497449 - 2¹² = 640493353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640497469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56297 + ... + 66710.

It is an arithmetic number, because the mean of its divisors is an integer number (82661376).

Almost surely, 2^640497449 is an apocalyptic number.

It is an amenable number.

640497449 is a deficient number, since it is larger than the sum of its proper divisors (20793559).

640497449 is a wasteful number, since it uses less digits than its factorization.

640497449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123175.

The product of its (nonzero) digits is 870912, while the sum is 47.

The square root of 640497449 is about 25308.0510707561. The cubic root of 640497449 is about 861.9970934777.

The spelling of 640497449 in words is "six hundred forty million, four hundred ninety-seven thousand, four hundred forty-nine".