1649787720 has 64 divisors (see below), whose sum is σ = 5656417920. Its totient is φ = 377094144.

The previous prime is 1649787719. The next prime is 1649787767. The reversal of 1649787720 is 277879461.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 981177 + ... + 982856.

It is an arithmetic number, because the mean of its divisors is an integer number (88381530).

Almost surely, 2^1649787720 is an apocalyptic number.

1649787720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1649787720 is an abundant number, since it is smaller than the sum of its proper divisors (4006630200).

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

1649787720 is a wasteful number, since it uses less digits than its factorization.

1649787720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1964054 (or 1964050 counting only the distinct ones).

The product of its (nonzero) digits is 1185408, while the sum is 51.

The square root of 1649787720 is about 40617.5789529607. The cubic root of 1649787720 is about 1181.6150727375.

The spelling of 1649787720 in words is "one billion, six hundred forty-nine million, seven hundred eighty-seven thousand, seven hundred twenty".