21240030634 has 8 divisors (see below), whose sum is σ = 32721128388. Its totient is φ = 10332987840.

The previous prime is 21240030611. The next prime is 21240030667. The reversal of 21240030634 is 43603004212.

It can be written as a sum of positive squares in 2 ways, for example, as 18226350025 + 3013680609 = 135005^2 + 54897^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21240030634² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21240030599 and 21240030608.

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, 143513647 + ... + 143513794.

Almost surely, 2^21240030634 is an apocalyptic number.

21240030634 is a deficient number, since it is larger than the sum of its proper divisors (11481097754).

21240030634 is a wasteful number, since it uses less digits than its factorization.

21240030634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287027480.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21240030634 its reverse (43603004212), we get a palindrome (64843034846).

The spelling of 21240030634 in words is "twenty-one billion, two hundred forty million, thirty thousand, six hundred thirty-four".