21561209482 has 8 divisors (see below), whose sum is σ = 32784852996. Its totient is φ = 10632925152.

The previous prime is 21561209479. The next prime is 21561209491. The reversal of 21561209482 is 28490216512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20517984081 + 1043225401 = 143241^2 + 32299^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73839613 + ... + 73839904.

Almost surely, 2^21561209482 is an apocalyptic number.

21561209482 is a deficient number, since it is larger than the sum of its proper divisors (11223643514).

21561209482 is a wasteful number, since it uses less digits than its factorization.

21561209482 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147679592.

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 21561209482 in words is "twenty-one billion, five hundred sixty-one million, two hundred nine thousand, four hundred eighty-two".