20201850021 has 4 divisors (see below), whose sum is σ = 26935800032. Its totient is φ = 13467900012.

The previous prime is 20201849999. The next prime is 20201850049. The reversal of 20201850021 is 12005810202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20201850021 - 2²³ = 20193461413 is a prime.

It is a super-2 number, since 2×20201850021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20201850021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20201850821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3366975001 + ... + 3366975006.

It is an arithmetic number, because the mean of its divisors is an integer number (6733950008).

Almost surely, 2^20201850021 is an apocalyptic number.

It is an amenable number.

20201850021 is a deficient number, since it is larger than the sum of its proper divisors (6733950011).

20201850021 is an equidigital number, since it uses as much as digits as its factorization.

20201850021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6733950010.

The product of its (nonzero) digits is 320, while the sum is 21.

The spelling of 20201850021 in words is "twenty billion, two hundred one million, eight hundred fifty thousand, twenty-one".