213131121001 has 4 divisors (see below), whose sum is σ = 213133164100. Its totient is φ = 213129077904.

The previous prime is 213131120977. The next prime is 213131121013. The reversal of 213131121001 is 100121131312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 209490205401 + 3640915600 = 457701^2 + 60340^2 .

It is a cyclic number.

It is not a de Polignac number, because 213131121001 - 2²³ = 213122732393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213131121031) 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, 856146 + ... + 1076683.

It is an arithmetic number, because the mean of its divisors is an integer number (53283291025).

Almost surely, 2^213131121001 is an apocalyptic number.

It is an amenable number.

213131121001 is a deficient number, since it is larger than the sum of its proper divisors (2043099).

213131121001 is a wasteful number, since it uses less digits than its factorization.

213131121001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043098.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 213131121001 its reverse (100121131312), we get a palindrome (313252252313).

The spelling of 213131121001 in words is "two hundred thirteen billion, one hundred thirty-one million, one hundred twenty-one thousand, one".