21520440034 has 8 divisors (see below), whose sum is σ = 32293859328. Its totient is φ = 10755820260.

The previous prime is 21520440023. The next prime is 21520440037. The reversal of 21520440034 is 43004402512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21520439990 and 21520440008.

It is not an unprimeable number, because it can be changed into a prime (21520440037) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2193762 + ... + 2203549.

It is an arithmetic number, because the mean of its divisors is an integer number (4036732416).

Almost surely, 2^21520440034 is an apocalyptic number.

21520440034 is a deficient number, since it is larger than the sum of its proper divisors (10773419294).

21520440034 is a wasteful number, since it uses less digits than its factorization.

21520440034 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4399760.

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21520440034 its reverse (43004402512), we get a palindrome (64524842546).

The spelling of 21520440034 in words is "twenty-one billion, five hundred twenty million, four hundred forty thousand, thirty-four".