21400240434 has 16 divisors (see below), whose sum is σ = 43127203680. Its totient is φ = 7078959680.

The previous prime is 21400240399. The next prime is 21400240439. The reversal of 21400240434 is 43404200412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21400240439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13612599 + ... + 13614170.

It is an arithmetic number, because the mean of its divisors is an integer number (2695450230).

Almost surely, 2^21400240434 is an apocalyptic number.

21400240434 is an abundant number, since it is smaller than the sum of its proper divisors (21726963246).

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

21400240434 is a wasteful number, since it uses less digits than its factorization.

21400240434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27226905.

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21400240434 its reverse (43404200412), we get a palindrome (64804440846).

The spelling of 21400240434 in words is "twenty-one billion, four hundred million, two hundred forty thousand, four hundred thirty-four".