31012221 has 8 divisors (see below), whose sum is σ = 41416704. Its totient is φ = 20641280.

The previous prime is 31012213. The next prime is 31012231. The reversal of 31012221 is 12221013.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31012221 - 2³ = 31012213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31012197 and 31012206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31012231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6141 + ... + 9986.

It is an arithmetic number, because the mean of its divisors is an integer number (5177088).

Almost surely, 2^31012221 is an apocalyptic number.

It is an amenable number.

31012221 is a deficient number, since it is larger than the sum of its proper divisors (10404483).

31012221 is a wasteful number, since it uses less digits than its factorization.

31012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16771.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 31012221 is about 5568.8617328858. The cubic root of 31012221 is about 314.1793402598.

Adding to 31012221 its reverse (12221013), we get a palindrome (43233234).

The spelling of 31012221 in words is "thirty-one million, twelve thousand, two hundred twenty-one".