21400124434 has 8 divisors (see below), whose sum is σ = 34569431820. Its totient is φ = 9876980496.

The previous prime is 21400124363. The next prime is 21400124539. The reversal of 21400124434 is 43442100412.

It can be written as a sum of positive squares in 2 ways, for example, as 19361331025 + 2038793409 = 139145^2 + 45153^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21400124399 and 21400124408.

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, 411540829 + ... + 411540880.

Almost surely, 2^21400124434 is an apocalyptic number.

21400124434 is a deficient number, since it is larger than the sum of its proper divisors (13169307386).

21400124434 is a wasteful number, since it uses less digits than its factorization.

21400124434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823081724.

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21400124434 its reverse (43442100412), we get a palindrome (64842224846).

The spelling of 21400124434 in words is "twenty-one billion, four hundred million, one hundred twenty-four thousand, four hundred thirty-four".