21124306642 has 16 divisors (see below), whose sum is σ = 31753374840. Its totient is φ = 10539873792.

The previous prime is 21124306633. The next prime is 21124306667. The reversal of 21124306642 is 24660342112.

It can be written as a sum of positive squares in 4 ways, for example, as 21123424921 + 881721 = 145339^2 + 939^2 .

It is a super-2 number, since 2×21124306642² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1963534 + ... + 1974262.

Almost surely, 2^21124306642 is an apocalyptic number.

21124306642 is a deficient number, since it is larger than the sum of its proper divisors (10629068198).

21124306642 is a wasteful number, since it uses less digits than its factorization.

21124306642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12717.

The product of its (nonzero) digits is 13824, while the sum is 31.

Adding to 21124306642 its reverse (24660342112), we get a palindrome (45784648754).

The spelling of 21124306642 in words is "twenty-one billion, one hundred twenty-four million, three hundred six thousand, six hundred forty-two".