31490321 has 4 divisors (see below), whose sum is σ = 32084532. Its totient is φ = 30896112.

The previous prime is 31490299. The next prime is 31490323. The reversal of 31490321 is 12309413.

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 20830096 + 10660225 = 4564^2 + 3265^2 .

It is a cyclic number.

It is not a de Polignac number, because 31490321 - 2⁶ = 31490257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31490323) 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, 297026 + ... + 297131.

It is an arithmetic number, because the mean of its divisors is an integer number (8021133).

Almost surely, 2^31490321 is an apocalyptic number.

It is an amenable number.

31490321 is a deficient number, since it is larger than the sum of its proper divisors (594211).

31490321 is an equidigital number, since it uses as much as digits as its factorization.

31490321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594210.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 31490321 is about 5611.6237400596. The cubic root of 31490321 is about 315.7856294556.

Adding to 31490321 its reverse (12309413), we get a palindrome (43799734).

The spelling of 31490321 in words is "thirty-one million, four hundred ninety thousand, three hundred twenty-one".