21208226051 has 8 divisors (see below), whose sum is σ = 21285695808. Its totient is φ = 21130888000.

The previous prime is 21208226047. The next prime is 21208226099. The reversal of 21208226051 is 15062280212.

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

It is a cyclic number.

It is not a de Polignac number, because 21208226051 - 2² = 21208226047 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21298226051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 295661 + ... + 360321.

It is an arithmetic number, because the mean of its divisors is an integer number (2660711976).

Almost surely, 2^21208226051 is an apocalyptic number.

21208226051 is a deficient number, since it is larger than the sum of its proper divisors (77469757).

21208226051 is an equidigital number, since it uses as much as digits as its factorization.

21208226051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65853.

The product of its (nonzero) digits is 3840, while the sum is 29.

The spelling of 21208226051 in words is "twenty-one billion, two hundred eight million, two hundred twenty-six thousand, fifty-one".