20121002001 has 24 divisors (see below), whose sum is σ = 30882103200. Its totient is φ = 12580304256.

The previous prime is 20121001987. The next prime is 20121002003. The reversal of 20121002001 is 10020012102.

It is not a de Polignac number, because 20121002001 - 2⁹ = 20121001489 is a prime.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20121002003) 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, 189051 + ... + 275648.

It is an arithmetic number, because the mean of its divisors is an integer number (1286754300).

Almost surely, 2^20121002001 is an apocalyptic number.

It is an amenable number.

20121002001 is a deficient number, since it is larger than the sum of its proper divisors (10761101199).

20121002001 is a wasteful number, since it uses less digits than its factorization.

20121002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465005 (or 465002 counting only the distinct ones).

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

Adding to 20121002001 its reverse (10020012102), we get a palindrome (30141014103).

The spelling of 20121002001 in words is "twenty billion, one hundred twenty-one million, two thousand, one".