21110020021 has 8 divisors (see below), whose sum is σ = 21311905824. Its totient is φ = 20908751760.

The previous prime is 21110020013. The next prime is 21110020037. The reversal of 21110020021 is 12002001112.

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 21110020021 - 2³ = 21110020013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110020621) 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, 85546 + ... + 222571.

It is an arithmetic number, because the mean of its divisors is an integer number (2663988228).

Almost surely, 2^21110020021 is an apocalyptic number.

It is an amenable number.

21110020021 is a deficient number, since it is larger than the sum of its proper divisors (201885803).

21110020021 is a wasteful number, since it uses less digits than its factorization.

21110020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308771.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21110020021 its reverse (12002001112), we get a palindrome (33112021133).

The spelling of 21110020021 in words is "twenty-one billion, one hundred ten million, twenty thousand, twenty-one".