8421218901 has 24 divisors (see below), whose sum is σ = 12296358360. Its totient is φ = 5553225216.

The previous prime is 8421218891. The next prime is 8421218941. The reversal of 8421218901 is 1098121248.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 558140625 + 7863078276 = 23625^2 + 88674^2 .

It is not a de Polignac number, because 8421218901 - 2⁶ = 8421218837 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8421218941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 598321 + ... + 612233.

It is an arithmetic number, because the mean of its divisors is an integer number (512348265).

Almost surely, 2^8421218901 is an apocalyptic number.

It is an amenable number.

8421218901 is a deficient number, since it is larger than the sum of its proper divisors (3875139459).

8421218901 is a wasteful number, since it uses less digits than its factorization.

8421218901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14645 (or 14642 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 8421218901 is about 91767.1994832576. The cubic root of 8421218901 is about 2034.5029262827.

The spelling of 8421218901 in words is "eight billion, four hundred twenty-one million, two hundred eighteen thousand, nine hundred one".