649297728 has 336 divisors, whose sum is σ = 2179198080. Its totient is φ = 188559360.

The previous prime is 649297717. The next prime is 649297729. The reversal of 649297728 is 827792946.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649297729) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20945073 + ... + 20945103.

Almost surely, 2^649297728 is an apocalyptic number.

649297728 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649297728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1089599040).

649297728 is an abundant number, since it is smaller than the sum of its proper divisors (1529900352).

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

649297728 is a wasteful number, since it uses less digits than its factorization.

649297728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 76 counting only the distinct ones).

The product of its digits is 3048192, while the sum is 54.

The square root of 649297728 is about 25481.3211588410. The cubic root of 649297728 is about 865.9270260146.

The spelling of 649297728 in words is "six hundred forty-nine million, two hundred ninety-seven thousand, seven hundred twenty-eight".