31213403 has 4 divisors (see below), whose sum is σ = 33614448. Its totient is φ = 28812360.

The previous prime is 31213397. The next prime is 31213417. The reversal of 31213403 is 30431213.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30431213 = 857 ⋅35509.

It is a cyclic number.

It is not a de Polignac number, because 31213403 - 2²⁴ = 14436187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31213433) 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, 1200503 + ... + 1200528.

It is an arithmetic number, because the mean of its divisors is an integer number (8403612).

Almost surely, 2^31213403 is an apocalyptic number.

31213403 is a deficient number, since it is larger than the sum of its proper divisors (2401045).

31213403 is a wasteful number, since it uses less digits than its factorization.

31213403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2401044.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 31213403 is about 5586.8956496430. The cubic root of 31213403 is about 314.8572562284.

Adding to 31213403 its reverse (30431213), we get a palindrome (61644616).

The spelling of 31213403 in words is "thirty-one million, two hundred thirteen thousand, four hundred three".