21620655206 has 4 divisors (see below), whose sum is σ = 32430982812. Its totient is φ = 10810327602.

The previous prime is 21620655187. The next prime is 21620655229. The reversal of 21620655206 is 60255602612.

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, 5405163800 + ... + 5405163803.

It is an arithmetic number, because the mean of its divisors is an integer number (8107745703).

Almost surely, 2^21620655206 is an apocalyptic number.

21620655206 is a deficient number, since it is larger than the sum of its proper divisors (10810327606).

21620655206 is a wasteful number, since it uses less digits than its factorization.

21620655206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10810327605.

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 21620655206 in words is "twenty-one billion, six hundred twenty million, six hundred fifty-five thousand, two hundred six".