21220354534 has 8 divisors (see below), whose sum is σ = 32370032520. Its totient is φ = 10430343696.

The previous prime is 21220354523. The next prime is 21220354537. The reversal of 21220354534 is 43545302212.

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 = 21220354496 and 21220354505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220354537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89916639 + ... + 89916874.

It is an arithmetic number, because the mean of its divisors is an integer number (4046254065).

Almost surely, 2^21220354534 is an apocalyptic number.

21220354534 is a deficient number, since it is larger than the sum of its proper divisors (11149677986).

21220354534 is a wasteful number, since it uses less digits than its factorization.

21220354534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179833574.

The product of its (nonzero) digits is 28800, while the sum is 31.

Adding to 21220354534 its reverse (43545302212), we get a palindrome (64765656746).

The spelling of 21220354534 in words is "twenty-one billion, two hundred twenty million, three hundred fifty-four thousand, five hundred thirty-four".