649720428 has 96 divisors (see below), whose sum is σ = 1858429440. Its totient is φ = 172523520.

The previous prime is 649720427. The next prime is 649720441. The reversal of 649720428 is 824027946.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 649720428.

It is not an unprimeable number, because it can be changed into a prime (649720427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80748 + ... + 88428.

It is an arithmetic number, because the mean of its divisors is an integer number (19358640).

Almost surely, 2^649720428 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 649720428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (929214720).

649720428 is an abundant number, since it is smaller than the sum of its proper divisors (1208709012).

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

649720428 is a wasteful number, since it uses less digits than its factorization.

649720428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7767 (or 7765 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 42.

The square root of 649720428 is about 25489.6141202647. The cubic root of 649720428 is about 866.1148946084.

The spelling of 649720428 in words is "six hundred forty-nine million, seven hundred twenty thousand, four hundred twenty-eight".