21558442040206 has 4 divisors (see below), whose sum is σ = 32337663060312. Its totient is φ = 10779221020102.

The previous prime is 21558442040167. The next prime is 21558442040221. The reversal of 21558442040206 is 60204024485512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5389610510050 + ... + 5389610510053.

It is an arithmetic number, because the mean of its divisors is an integer number (8084415765078).

Almost surely, 2^{21558442040206} is an apocalyptic number.

21558442040206 is a deficient number, since it is larger than the sum of its proper divisors (10779221020106).

21558442040206 is a wasteful number, since it uses less digits than its factorization.

21558442040206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10779221020105.

The product of its (nonzero) digits is 614400, while the sum is 43.

The spelling of 21558442040206 in words is "twenty-one trillion, five hundred fifty-eight billion, four hundred forty-two million, forty thousand, two hundred six".