21002386084 has 9 divisors (see below), whose sum is σ = 36754682881. Its totient is φ = 10501048120.

The previous prime is 21002386081. The next prime is 21002386091. The reversal of 21002386084 is 48068320012.

The square root of 21002386084 is 144922.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 20886608484 + 115777600 = 144522^2 + 10760^2 .

It is a super-2 number, since 2×21002386084² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002386081) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 253614 + ... + 326074.

Almost surely, 2^21002386084 is an apocalyptic number.

21002386084 is the 144922-nd square number.

It is an amenable number.

21002386084 is a deficient number, since it is larger than the sum of its proper divisors (15752296797).

21002386084 is an frugal number, since it uses more digits than its factorization.

21002386084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144926 (or 72463 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 34.

The spelling of 21002386084 in words is "twenty-one billion, two million, three hundred eighty-six thousand, eighty-four".