21530013154 has 16 divisors (see below), whose sum is σ = 36825091128. Its totient is φ = 9352403712.

The previous prime is 21530013149. The next prime is 21530013157. The reversal of 21530013154 is 45131003512.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17024247529 + 4505765625 = 130477^2 + 67125^2 .

It is a super-2 number, since 2×21530013154² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21530013157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24354777 + ... + 24355660.

Almost surely, 2^21530013154 is an apocalyptic number.

21530013154 is a deficient number, since it is larger than the sum of its proper divisors (15295077974).

21530013154 is a wasteful number, since it uses less digits than its factorization.

21530013154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48710469.

The product of its (nonzero) digits is 1800, while the sum is 25.

Adding to 21530013154 its reverse (45131003512), we get a palindrome (66661016666).

The spelling of 21530013154 in words is "twenty-one billion, five hundred thirty million, thirteen thousand, one hundred fifty-four".