21245050021 has 8 divisors (see below), whose sum is σ = 23874036480. Its totient is φ = 18758170992.

The previous prime is 21245049977. The next prime is 21245050037. The reversal of 21245050021 is 12005054212.

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 21245050021 - 2⁷ = 21245049893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21245049974 and 21245050001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245057021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35526541 + ... + 35527138.

It is an arithmetic number, because the mean of its divisors is an integer number (2984254560).

Almost surely, 2^21245050021 is an apocalyptic number.

It is an amenable number.

21245050021 is a deficient number, since it is larger than the sum of its proper divisors (2628986459).

21245050021 is a wasteful number, since it uses less digits than its factorization.

21245050021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71053715.

The product of its (nonzero) digits is 800, while the sum is 22.

The spelling of 21245050021 in words is "twenty-one billion, two hundred forty-five million, fifty thousand, twenty-one".