649971616 has 48 divisors (see below), whose sum is σ = 1468938240. Its totient is φ = 277320960.

The previous prime is 649971613. The next prime is 649971629. The reversal of 649971616 is 616179946.

It is a self number, because there is not a number n which added to its sum of digits gives 649971616.

It is not an unprimeable number, because it can be changed into a prime (649971613) 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, 44961 + ... + 57631.

It is an arithmetic number, because the mean of its divisors is an integer number (30602880).

Almost surely, 2^649971616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649971616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (734469120).

649971616 is an abundant number, since it is smaller than the sum of its proper divisors (818966624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649971616 is a wasteful number, since it uses less digits than its factorization.

649971616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12917 (or 12909 counting only the distinct ones).

The product of its digits is 489888, while the sum is 49.

The square root of 649971616 is about 25494.5409058488. The cubic root of 649971616 is about 866.2264962698.

The spelling of 649971616 in words is "six hundred forty-nine million, nine hundred seventy-one thousand, six hundred sixteen".