21561209483 has 8 divisors (see below), whose sum is σ = 23615032896. Its totient is φ = 19523005000.

The previous prime is 21561209479. The next prime is 21561209491. The reversal of 21561209483 is 38490216512.

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

It is a cyclic number.

It is not a de Polignac number, because 21561209483 - 2² = 21561209479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21561209483.

It is not an unprimeable number, because it can be changed into a prime (21561209083) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3901841 + ... + 3907362.

It is an arithmetic number, because the mean of its divisors is an integer number (2951879112).

Almost surely, 2^21561209483 is an apocalyptic number.

21561209483 is a deficient number, since it is larger than the sum of its proper divisors (2053823413).

21561209483 is a wasteful number, since it uses less digits than its factorization.

21561209483 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7809465.

The product of its (nonzero) digits is 103680, while the sum is 41.

The spelling of 21561209483 in words is "twenty-one billion, five hundred sixty-one million, two hundred nine thousand, four hundred eighty-three".