21251151234 has 12 divisors (see below), whose sum is σ = 46044161046. Its totient is φ = 7083717072.

The previous prime is 21251151227. The next prime is 21251151239. The reversal of 21251151234 is 43215115212.

It is a happy number.

21251151234 is a `hidden beast` number, since 21 + 2 + 511 + 5 + 123 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14726550609 + 6524600625 = 121353^2 + 80775^2 .

It is a super-2 number, since 2×21251151234² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21251151198 and 21251151207.

It is not an unprimeable number, because it can be changed into a prime (21251151239) 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 5 ways as a sum of consecutive naturals, for example, 590309739 + ... + 590309774.

Almost surely, 2^21251151234 is an apocalyptic number.

21251151234 is an abundant number, since it is smaller than the sum of its proper divisors (24793009812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21251151234 is a wasteful number, since it uses less digits than its factorization.

21251151234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180619521 (or 1180619518 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

Adding to 21251151234 its reverse (43215115212), we get a palindrome (64466266446).

The spelling of 21251151234 in words is "twenty-one billion, two hundred fifty-one million, one hundred fifty-one thousand, two hundred thirty-four".