1201210100001 has 20 divisors (see below), whose sum is σ = 1872417678912. Its totient is φ = 765989048088.

The previous prime is 1201210099987. The next prime is 1201210100081. The reversal of 1201210100001 is 1000010121021.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-1201210100001 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 (1201210100081) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 322384101 + ... + 322387826.

Almost surely, 2^{1201210100001} is an apocalyptic number.

It is an amenable number.

1201210100001 is a deficient number, since it is larger than the sum of its proper divisors (671207578911).

1201210100001 is an equidigital number, since it uses as much as digits as its factorization.

1201210100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644771962 (or 644771953 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1201210100001 its reverse (1000010121021), we get a palindrome (2201220221022).

The spelling of 1201210100001 in words is "one trillion, two hundred one billion, two hundred ten million, one hundred thousand, one".