31422291821 has 2 divisors, whose sum is σ = 31422291822. Its totient is φ = 31422291820.

The previous prime is 31422291809. The next prime is 31422291913. The reversal of 31422291821 is 12819222413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16585833796 + 14836458025 = 128786^2 + 121805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31422291821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31422291221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15711145910 + 15711145911.

It is an arithmetic number, because the mean of its divisors is an integer number (15711145911).

Almost surely, 2^31422291821 is an apocalyptic number.

It is an amenable number.

31422291821 is a deficient number, since it is larger than the sum of its proper divisors (1).

31422291821 is an equidigital number, since it uses as much as digits as its factorization.

31422291821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 35.

The spelling of 31422291821 in words is "thirty-one billion, four hundred twenty-two million, two hundred ninety-one thousand, eight hundred twenty-one".