1211312001 has 4 divisors (see below), whose sum is σ = 1615082672. Its totient is φ = 807541332.

The previous prime is 1211311993. The next prime is 1211312009. The reversal of 1211312001 is 1002131121.

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 an interprime number because it is at equal distance from previous prime (1211311993) and next prime (1211312009).

It is not a de Polignac number, because 1211312001 - 2³ = 1211311993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211312009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201885331 + ... + 201885336.

It is an arithmetic number, because the mean of its divisors is an integer number (403770668).

Almost surely, 2^1211312001 is an apocalyptic number.

It is an amenable number.

1211312001 is a deficient number, since it is larger than the sum of its proper divisors (403770671).

1211312001 is an equidigital number, since it uses as much as digits as its factorization.

1211312001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403770670.

The product of its (nonzero) digits is 12, while the sum is 12.

The square root of 1211312001 is about 34803.9078409307. The cubic root of 1211312001 is about 1065.9872412282.

Adding to 1211312001 its reverse (1002131121), we get a palindrome (2213443122).

The spelling of 1211312001 in words is "one billion, two hundred eleven million, three hundred twelve thousand, one".