649681577 has 16 divisors (see below), whose sum is σ = 684547200. Its totient is φ = 615753600.

The previous prime is 649681561. The next prime is 649681597. The reversal of 649681577 is 775186946.

It is a cyclic number.

It is not a de Polignac number, because 649681577 - 2⁴ = 649681561 is a prime.

It is a super-4 number, since 4×649681577⁴ (a number of 36 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649681597) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 388898 + ... + 390564.

It is an arithmetic number, because the mean of its divisors is an integer number (42784200).

Almost surely, 2^649681577 is an apocalyptic number.

It is an amenable number.

649681577 is a deficient number, since it is larger than the sum of its proper divisors (34865623).

649681577 is a wasteful number, since it uses less digits than its factorization.

649681577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1936.

The product of its digits is 2540160, while the sum is 53.

The square root of 649681577 is about 25488.8520141649. The cubic root of 649681577 is about 866.0976307213.

The spelling of 649681577 in words is "six hundred forty-nine million, six hundred eighty-one thousand, five hundred seventy-seven".