6499987890 has 128 divisors (see below), whose sum is σ = 17674723584. Its totient is φ = 1516032000.

The previous prime is 6499987873. The next prime is 6499987969. The reversal of 6499987890 is 987899946.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 984400 + ... + 990980.

It is an arithmetic number, because the mean of its divisors is an integer number (138083778).

Almost surely, 2^6499987890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6499987890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8837361792).

6499987890 is an abundant number, since it is smaller than the sum of its proper divisors (11174735694).

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

6499987890 is a wasteful number, since it uses less digits than its factorization.

6499987890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6716.

The product of its (nonzero) digits is 70543872, while the sum is 69.

The square root of 6499987890 is about 80622.5023799187. The cubic root of 6499987890 is about 1866.2544194153.

The spelling of 6499987890 in words is "six billion, four hundred ninety-nine million, nine hundred eighty-seven thousand, eight hundred ninety".