21020420248 has 16 divisors (see below), whose sum is σ = 40251869280. Its totient is φ = 10286588448.

The previous prime is 21020420237. The next prime is 21020420249. The reversal of 21020420248 is 84202402012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020420249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27952311 + ... + 27953062.

It is an arithmetic number, because the mean of its divisors is an integer number (2515741830).

Almost surely, 2^21020420248 is an apocalyptic number.

It is an amenable number.

21020420248 is a deficient number, since it is larger than the sum of its proper divisors (19231449032).

21020420248 is a wasteful number, since it uses less digits than its factorization.

21020420248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55905426 (or 55905422 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 25.

The spelling of 21020420248 in words is "twenty-one billion, twenty million, four hundred twenty thousand, two hundred forty-eight".