31000221013 has 2 divisors, whose sum is σ = 31000221014. Its totient is φ = 31000221012.

The previous prime is 31000220983. The next prime is 31000221029. The reversal of 31000221013 is 31012200013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24174652324 + 6825568689 = 155482^2 + 82617^2 .

It is an emirp because it is prime and its reverse (31012200013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31000221013 - 2¹³ = 31000212821 is a prime.

It is a super-2 number, since 2×31000221013² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31000220984 and 31000221002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31000221053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15500110506 + 15500110507.

It is an arithmetic number, because the mean of its divisors is an integer number (15500110507).

Almost surely, 2^31000221013 is an apocalyptic number.

It is an amenable number.

31000221013 is a deficient number, since it is larger than the sum of its proper divisors (1).

31000221013 is an equidigital number, since it uses as much as digits as its factorization.

31000221013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 31000221013 its reverse (31012200013), we get a palindrome (62012421026).

The spelling of 31000221013 in words is "thirty-one billion, two hundred twenty-one thousand, thirteen".