31270221 has 6 divisors (see below), whose sum is σ = 45168110. Its totient is φ = 20846808.

The previous prime is 31270201. The next prime is 31270223. The reversal of 31270221 is 12207213.

It can be written as a sum of positive squares in only one way, i.e., 24950025 + 6320196 = 4995^2 + 2514^2 .

It is not a de Polignac number, because 31270221 - 2¹⁷ = 31139149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31270194 and 31270203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31270223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1737226 + ... + 1737243.

Almost surely, 2^31270221 is an apocalyptic number.

It is an amenable number.

31270221 is a deficient number, since it is larger than the sum of its proper divisors (13897889).

31270221 is a wasteful number, since it uses less digits than its factorization.

31270221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3474475 (or 3474472 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 31270221 is about 5591.9782724900. The cubic root of 31270221 is about 315.0481861281.

Adding to 31270221 its reverse (12207213), we get a palindrome (43477434).

The spelling of 31270221 in words is "thirty-one million, two hundred seventy thousand, two hundred twenty-one".