31211421 has 16 divisors (see below), whose sum is σ = 42774336. Its totient is φ = 20232576.

The previous prime is 31211417. The next prime is 31211423. The reversal of 31211421 is 12411213.

It is not a de Polignac number, because 31211421 - 2² = 31211417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31211421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31211423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39991 + ... + 40763.

It is an arithmetic number, because the mean of its divisors is an integer number (2673396).

Almost surely, 2^31211421 is an apocalyptic number.

It is an amenable number.

31211421 is a deficient number, since it is larger than the sum of its proper divisors (11562915).

31211421 is a wasteful number, since it uses less digits than its factorization.

31211421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1132.

The product of its digits is 48, while the sum is 15.

The square root of 31211421 is about 5586.7182674626. The cubic root of 31211421 is about 314.8505917805.

Adding to 31211421 its reverse (12411213), we get a palindrome (43622634).

The spelling of 31211421 in words is "thirty-one million, two hundred eleven thousand, four hundred twenty-one".