1631210121 has 12 divisors (see below), whose sum is σ = 2357126772. Its totient is φ = 1087042176.

The previous prime is 1631210099. The next prime is 1631210143. The reversal of 1631210121 is 1210121361.

1631210121 is a `hidden beast` number, since 1 + 631 + 2 + 10 + 1 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (1631210099) and next prime (1631210143).

It can be written as a sum of positive squares in 2 ways, for example, as 1477326096 + 153884025 = 38436^2 + 12405^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1631210121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1631210094 and 1631210103.

It is not an unprimeable number, because it can be changed into a prime (1631210171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11076 + ... + 58181.

It is an arithmetic number, because the mean of its divisors is an integer number (196427231).

Almost surely, 2^1631210121 is an apocalyptic number.

It is an amenable number.

1631210121 is a deficient number, since it is larger than the sum of its proper divisors (725916651).

1631210121 is a wasteful number, since it uses less digits than its factorization.

1631210121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71880 (or 71877 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 1631210121 is about 40388.2423608654. The cubic root of 1631210121 is about 1177.1630885945.

Adding to 1631210121 its reverse (1210121361), we get a palindrome (2841331482).

The spelling of 1631210121 in words is "one billion, six hundred thirty-one million, two hundred ten thousand, one hundred twenty-one".