20424557021 has 8 divisors (see below), whose sum is σ = 22755406464. Its totient is φ = 18172719520.

The previous prime is 20424556973. The next prime is 20424557033. The reversal of 20424557021 is 12075542402.

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 20424557021 - 2¹⁰ = 20424555997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20424557071) 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, 19752440 + ... + 19753473.

It is an arithmetic number, because the mean of its divisors is an integer number (2844425808).

Almost surely, 2^20424557021 is an apocalyptic number.

It is an amenable number.

20424557021 is a deficient number, since it is larger than the sum of its proper divisors (2330849443).

20424557021 is a wasteful number, since it uses less digits than its factorization.

20424557021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39505971.

The product of its (nonzero) digits is 22400, while the sum is 32.

The spelling of 20424557021 in words is "twenty billion, four hundred twenty-four million, five hundred fifty-seven thousand, twenty-one".