31201011221 has 4 divisors (see below), whose sum is σ = 31208809632. Its totient is φ = 31193212812.

The previous prime is 31201011197. The next prime is 31201011269. The reversal of 31201011221 is 12211010213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31201011221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31201011196 and 31201011205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31201010221) 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, 3893201 + ... + 3901206.

It is an arithmetic number, because the mean of its divisors is an integer number (7802202408).

Almost surely, 2^31201011221 is an apocalyptic number.

It is an amenable number.

31201011221 is a deficient number, since it is larger than the sum of its proper divisors (7798411).

31201011221 is an equidigital number, since it uses as much as digits as its factorization.

31201011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7798410.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 31201011221 its reverse (12211010213), we get a palindrome (43412021434).

The spelling of 31201011221 in words is "thirty-one billion, two hundred one million, eleven thousand, two hundred twenty-one".