31820378101 has 2 divisors, whose sum is σ = 31820378102. Its totient is φ = 31820378100.

The previous prime is 31820378063. The next prime is 31820378147. The reversal of 31820378101 is 10187302813.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24759337201 + 7061040900 = 157351^2 + 84030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31820378101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31820375101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15910189050 + 15910189051.

It is an arithmetic number, because the mean of its divisors is an integer number (15910189051).

Almost surely, 2^31820378101 is an apocalyptic number.

It is an amenable number.

31820378101 is a deficient number, since it is larger than the sum of its proper divisors (1).

31820378101 is an equidigital number, since it uses as much as digits as its factorization.

31820378101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 34.

The spelling of 31820378101 in words is "thirty-one billion, eight hundred twenty million, three hundred seventy-eight thousand, one hundred one".