31820478869 has 2 divisors, whose sum is σ = 31820478870. Its totient is φ = 31820478868.

The previous prime is 31820478769. The next prime is 31820478917. The reversal of 31820478869 is 96887402813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31635246769 + 185232100 = 177863^2 + 13610^2 .

It is a cyclic number.

It is not a de Polignac number, because 31820478869 - 2¹⁶ = 31820413333 is a prime.

It is a super-2 number, since 2×31820478869² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31820478169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15910239434 + 15910239435.

It is an arithmetic number, because the mean of its divisors is an integer number (15910239435).

Almost surely, 2^31820478869 is an apocalyptic number.

It is an amenable number.

31820478869 is a deficient number, since it is larger than the sum of its proper divisors (1).

31820478869 is an equidigital number, since it uses as much as digits as its factorization.

31820478869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4644864, while the sum is 56.

The spelling of 31820478869 in words is "thirty-one billion, eight hundred twenty million, four hundred seventy-eight thousand, eight hundred sixty-nine".