21002140434 has 32 divisors (see below), whose sum is σ = 46337728320. Its totient is φ = 6292774400.

The previous prime is 21002140433. The next prime is 21002140469. The reversal of 21002140434 is 43404120012.

21002140434 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 21002140434.

It is not an unprimeable number, because it can be changed into a prime (21002140433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1781847 + ... + 1793594.

It is an arithmetic number, because the mean of its divisors is an integer number (1448054010).

Almost surely, 2^21002140434 is an apocalyptic number.

21002140434 is an abundant number, since it is smaller than the sum of its proper divisors (25335587886).

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

21002140434 is a wasteful number, since it uses less digits than its factorization.

21002140434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3575546.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21002140434 its reverse (43404120012), we get a palindrome (64406260446).

The spelling of 21002140434 in words is "twenty-one billion, two million, one hundred forty thousand, four hundred thirty-four".