31121201 has 4 divisors (see below), whose sum is σ = 31132404. Its totient is φ = 31110000.

The previous prime is 31121197. The next prime is 31121249. The reversal of 31121201 is 10212113.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6370576 + 24750625 = 2524^2 + 4975^2 .

It is a cyclic number.

It is not a de Polignac number, because 31121201 - 2² = 31121197 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31121281) 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, 2051 + ... + 8151.

It is an arithmetic number, because the mean of its divisors is an integer number (7783101).

Almost surely, 2^31121201 is an apocalyptic number.

It is an amenable number.

31121201 is a deficient number, since it is larger than the sum of its proper divisors (11203).

31121201 is an equidigital number, since it uses as much as digits as its factorization.

31121201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11202.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 31121201 is about 5578.6379161942. The cubic root of 31121201 is about 314.5469290661.

Adding to 31121201 its reverse (10212113), we get a palindrome (41333314).

It can be divided in two parts, 311 and 21201, that added together give a palindrome (21512).

The spelling of 31121201 in words is "thirty-one million, one hundred twenty-one thousand, two hundred one".