8638421660 has 48 divisors (see below), whose sum is σ = 19796337792. Its totient is φ = 3140212800.

The previous prime is 8638421647. The next prime is 8638421663. The reversal of 8638421660 is 661248368.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8638421663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1080839 + ... + 1088801.

It is an arithmetic number, because the mean of its divisors is an integer number (412423704).

Almost surely, 2^8638421660 is an apocalyptic number.

It is an amenable number.

8638421660 is an abundant number, since it is smaller than the sum of its proper divisors (11157916132).

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

8638421660 is a wasteful number, since it uses less digits than its factorization.

8638421660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12914 (or 12912 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 44.

The square root of 8638421660 is about 92943.1098037934. The cubic root of 8638421660 is about 2051.8461782436.

The spelling of 8638421660 in words is "eight billion, six hundred thirty-eight million, four hundred twenty-one thousand, six hundred sixty".