31213103 has 4 divisors (see below), whose sum is σ = 31332048. Its totient is φ = 31094160.

The previous prime is 31213099. The next prime is 31213109. The reversal of 31213103 is 30131213.

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

It is a cyclic number.

It is not a de Polignac number, because 31213103 - 2² = 31213099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213109) 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, 59078 + ... + 59603.

It is an arithmetic number, because the mean of its divisors is an integer number (7833012).

Almost surely, 2^31213103 is an apocalyptic number.

31213103 is a deficient number, since it is larger than the sum of its proper divisors (118945).

31213103 is a wasteful number, since it uses less digits than its factorization.

31213103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118944.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 31213103 is about 5586.8688010369. The cubic root of 31213103 is about 314.8562475006.

Adding to 31213103 its reverse (30131213), we get a palindrome (61344316).

The spelling of 31213103 in words is "thirty-one million, two hundred thirteen thousand, one hundred three".