4991649640 has 24 divisors (see below), whose sum is σ = 11232217170. Its totient is φ = 1996481120.

The previous prime is 4991649587. The next prime is 4991649647. The reversal of 4991649640 is 469461994.

It can be written as a sum of positive squares in only one way, i.e., 4492484676 + 499164964 = 67026^2 + 22342^2 .

It is a super-2 number, since 2×4991649640² = 49833132257024259200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (4991649647) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 441255 + ... + 452425.

Almost surely, 2^4991649640 is an apocalyptic number.

4991649640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

4991649640 is an abundant number, since it is smaller than the sum of its proper divisors (6240567530).

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

4991649640 is an frugal number, since it uses more digits than its factorization.

4991649640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22353 (or 11178 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 52.

The square root of 4991649640 is about 70651.6074834819. The cubic root of 4991649640 is about 1709.0234886055.

The spelling of 4991649640 in words is "four billion, nine hundred ninety-one million, six hundred forty-nine thousand, six hundred forty".