21535223546 has 4 divisors (see below), whose sum is σ = 32302835322. Its totient is φ = 10767611772.

The previous prime is 21535223539. The next prime is 21535223557. The reversal of 21535223546 is 64532253512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18533827321 + 3001396225 = 136139^2 + 54785^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5383805885 + ... + 5383805888.

Almost surely, 2^21535223546 is an apocalyptic number.

21535223546 is a deficient number, since it is larger than the sum of its proper divisors (10767611776).

21535223546 is a wasteful number, since it uses less digits than its factorization.

21535223546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10767611775.

The product of its digits is 216000, while the sum is 38.

The spelling of 21535223546 in words is "twenty-one billion, five hundred thirty-five million, two hundred twenty-three thousand, five hundred forty-six".