649721305 has 8 divisors (see below), whose sum is σ = 782422272. Its totient is φ = 517939248.

The previous prime is 649721297. The next prime is 649721323. The reversal of 649721305 is 503127946.

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 649721305 - 2³ = 649721297 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 228169 + ... + 230998.

It is an arithmetic number, because the mean of its divisors is an integer number (97802784).

Almost surely, 2^649721305 is an apocalyptic number.

It is an amenable number.

649721305 is a deficient number, since it is larger than the sum of its proper divisors (132700967).

649721305 is a wasteful number, since it uses less digits than its factorization.

649721305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459455.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 649721305 is about 25489.6313233440. The cubic root of 649721305 is about 866.1152843055.

The spelling of 649721305 in words is "six hundred forty-nine million, seven hundred twenty-one thousand, three hundred five".