21220208061 has 16 divisors (see below), whose sum is σ = 32262398784. Its totient is φ = 12290436864.

The previous prime is 21220208039. The next prime is 21220208099. The reversal of 21220208061 is 16080202212.

It is not a de Polignac number, because 21220208061 - 2¹¹ = 21220206013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220208021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16002511 + ... + 16003836.

It is an arithmetic number, because the mean of its divisors is an integer number (2016399924).

Almost surely, 2^21220208061 is an apocalyptic number.

It is an amenable number.

21220208061 is a deficient number, since it is larger than the sum of its proper divisors (11042190723).

21220208061 is a wasteful number, since it uses less digits than its factorization.

21220208061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32006380.

The product of its (nonzero) digits is 768, while the sum is 24.

The spelling of 21220208061 in words is "twenty-one billion, two hundred twenty million, two hundred eight thousand, sixty-one".