31230121 has 4 divisors (see below), whose sum is σ = 33632452. Its totient is φ = 28827792.

The previous prime is 31230079. The next prime is 31230163. The reversal of 31230121 is 12103213.

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

It is an interprime number because it is at equal distance from previous prime (31230079) and next prime (31230163).

It can be written as a sum of positive squares in 2 ways, for example, as 20602521 + 10627600 = 4539^2 + 3260^2 .

It is a cyclic number.

It is not a de Polignac number, because 31230121 - 2⁷ = 31229993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 2402317 = 31230121 / (3 + 1 + 2 + 3 + 0 + 1 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31230191) 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, 1201146 + ... + 1201171.

It is an arithmetic number, because the mean of its divisors is an integer number (8408113).

Almost surely, 2^31230121 is an apocalyptic number.

It is an amenable number.

31230121 is a deficient number, since it is larger than the sum of its proper divisors (2402331).

31230121 is a wasteful number, since it uses less digits than its factorization.

31230121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2402330.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 31230121 is about 5588.3916290826. The cubic root of 31230121 is about 314.9134590517.

Adding to 31230121 its reverse (12103213), we get a palindrome (43333334).

The spelling of 31230121 in words is "thirty-one million, two hundred thirty thousand, one hundred twenty-one".