21480390185 has 4 divisors (see below), whose sum is σ = 25776468228. Its totient is φ = 17184312144.

The previous prime is 21480390149. The next prime is 21480390223. The reversal of 21480390185 is 58109308412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4748450281 + 16731939904 = 68909^2 + 129352^2 .

It is a cyclic number.

It is not a de Polignac number, because 21480390185 - 2⁶ = 21480390121 is a prime.

It is a super-2 number, since 2×21480390185² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2148039014 + ... + 2148039023.

It is an arithmetic number, because the mean of its divisors is an integer number (6444117057).

Almost surely, 2^21480390185 is an apocalyptic number.

It is an amenable number.

21480390185 is a deficient number, since it is larger than the sum of its proper divisors (4296078043).

21480390185 is an equidigital number, since it uses as much as digits as its factorization.

21480390185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4296078042.

The product of its (nonzero) digits is 69120, while the sum is 41.

Adding to 21480390185 its reverse (58109308412), we get a palindrome (79589698597).

The spelling of 21480390185 in words is "twenty-one billion, four hundred eighty million, three hundred ninety thousand, one hundred eighty-five".