1649807640 has 96 divisors (see below), whose sum is σ = 5774343120. Its totient is φ = 406105344.

The previous prime is 1649807623. The next prime is 1649807657. The reversal of 1649807640 is 467089461.

It is an interprime number because it is at equal distance from previous prime (1649807623) and next prime (1649807657).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 171582 + ... + 180941.

Almost surely, 2^1649807640 is an apocalyptic number.

1649807640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1649807640 is an abundant number, since it is smaller than the sum of its proper divisors (4124535480).

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

1649807640 is a wasteful number, since it uses less digits than its factorization.

1649807640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352553 (or 352546 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 1649807640 is about 40617.8241662450. The cubic root of 1649807640 is about 1181.6198284357.

The spelling of 1649807640 in words is "one billion, six hundred forty-nine million, eight hundred seven thousand, six hundred forty".