20200121001 has 24 divisors (see below), whose sum is σ = 29254065984. Its totient is φ = 13431670560.

The previous prime is 20200120991. The next prime is 20200121009. The reversal of 20200121001 is 10012100202.

It is not a de Polignac number, because 20200121001 - 2⁷ = 20200120873 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (20200121009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9677980 + ... + 9680066.

It is an arithmetic number, because the mean of its divisors is an integer number (1218919416).

Almost surely, 2^20200121001 is an apocalyptic number.

It is an amenable number.

20200121001 is a deficient number, since it is larger than the sum of its proper divisors (9053944983).

20200121001 is a wasteful number, since it uses less digits than its factorization.

20200121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4381 (or 4378 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20200121001 its reverse (10012100202), we get a palindrome (30212221203).

The spelling of 20200121001 in words is "twenty billion, two hundred million, one hundred twenty-one thousand, one".