21123130434 has 32 divisors (see below), whose sum is σ = 48497971200. Its totient is φ = 6008113872.

The previous prime is 21123130387. The next prime is 21123130439. The reversal of 21123130434 is 43403132112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21123130439) 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, 1118284 + ... + 1137015.

It is an arithmetic number, because the mean of its divisors is an integer number (1515561600).

Almost surely, 2^21123130434 is an apocalyptic number.

21123130434 is an abundant number, since it is smaller than the sum of its proper divisors (27374840766).

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

21123130434 is a wasteful number, since it uses less digits than its factorization.

21123130434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2255534.

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21123130434 its reverse (43403132112), we get a palindrome (64526262546).

The spelling of 21123130434 in words is "twenty-one billion, one hundred twenty-three million, one hundred thirty thousand, four hundred thirty-four".