21011534430 has 64 divisors (see below), whose sum is σ = 52385356800. Its totient is φ = 5387177600.

The previous prime is 21011534339. The next prime is 21011534437. The reversal of 21011534430 is 3443511012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21011534430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011534437) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 157405 + ... + 258455.

It is an arithmetic number, because the mean of its divisors is an integer number (818521200).

Almost surely, 2^21011534430 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011534430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26192678400).

21011534430 is an abundant number, since it is smaller than the sum of its proper divisors (31373822370).

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

21011534430 is a wasteful number, since it uses less digits than its factorization.

21011534430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101329.

The product of its (nonzero) digits is 1440, while the sum is 24.

The spelling of 21011534430 in words is "twenty-one billion, eleven million, five hundred thirty-four thousand, four hundred thirty".