1649263440 has 80 divisors (see below), whose sum is σ = 5577518016. Its totient is φ = 399820800.

The previous prime is 1649263433. The next prime is 1649263459. The reversal of 1649263440 is 443629461.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

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, 309721 + ... + 315000.

Almost surely, 2^1649263440 is an apocalyptic number.

1649263440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1649263440 is an abundant number, since it is smaller than the sum of its proper divisors (3928254576).

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

1649263440 is a wasteful number, since it uses less digits than its factorization.

1649263440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624748 (or 624742 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 39.

The square root of 1649263440 is about 40611.1245842811. The cubic root of 1649263440 is about 1181.4898924336.

The spelling of 1649263440 in words is "one billion, six hundred forty-nine million, two hundred sixty-three thousand, four hundred forty".