21071029434 has 128 divisors (see below), whose sum is σ = 53585763840. Its totient is φ = 5374854144.

The previous prime is 21071029433. The next prime is 21071029439. The reversal of 21071029434 is 43492017012.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21071029395 and 21071029404.

It is not an unprimeable number, because it can be changed into a prime (21071029433) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3491932 + ... + 3497960.

It is an arithmetic number, because the mean of its divisors is an integer number (418638780).

Almost surely, 2^21071029434 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21071029434, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26792881920).

21071029434 is an abundant number, since it is smaller than the sum of its proper divisors (32514734406).

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

21071029434 is a wasteful number, since it uses less digits than its factorization.

21071029434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6264.

The product of its (nonzero) digits is 12096, while the sum is 33.

The spelling of 21071029434 in words is "twenty-one billion, seventy-one million, twenty-nine thousand, four hundred thirty-four".