21420130024 has 8 divisors (see below), whose sum is σ = 40162743810. Its totient is φ = 10710065008.

The previous prime is 21420130013. The next prime is 21420130057. The reversal of 21420130024 is 42003102412.

It can be written as a sum of positive squares in only one way, i.e., 19232697124 + 2187432900 = 138682^2 + 46770^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21420129983 and 21420130010.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1338758119 + ... + 1338758134.

Almost surely, 2^21420130024 is an apocalyptic number.

It is an amenable number.

21420130024 is a deficient number, since it is larger than the sum of its proper divisors (18742613786).

21420130024 is a wasteful number, since it uses less digits than its factorization.

21420130024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2677516259 (or 2677516255 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21420130024 its reverse (42003102412), we get a palindrome (63423232436).

The spelling of 21420130024 in words is "twenty-one billion, four hundred twenty million, one hundred thirty thousand, twenty-four".