649778240 has 56 divisors (see below), whose sum is σ = 1553501592. Its totient is φ = 258867200.

The previous prime is 649778219. The next prime is 649778249. The reversal of 649778240 is 42877946.

It can be written as a sum of positive squares in 4 ways, for example, as 300536896 + 349241344 = 17336^2 + 18688^2 .

It is a super-2 number, since 2×649778240² = 844423522354995200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (649778249) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 78290 + ... + 86190.

Almost surely, 2^649778240 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 649778240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (776750796).

649778240 is an abundant number, since it is smaller than the sum of its proper divisors (903723352).

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

649778240 is a wasteful number, since it uses less digits than its factorization.

649778240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8175 (or 8165 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 47.

The square root of 649778240 is about 25490.7481255455. The cubic root of 649778240 is about 866.1405827594.

The spelling of 649778240 in words is "six hundred forty-nine million, seven hundred seventy-eight thousand, two hundred forty".