61111111031 has 2 divisors, whose sum is σ = 61111111032. Its totient is φ = 61111111030.

The previous prime is 61111111027. The next prime is 61111111049. The reversal of 61111111031 is 13011111116.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61111111031 - 2² = 61111111027 is a prime.

It is a super-2 number, since 2×61111111031² (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 (61111111081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30555555515 + 30555555516.

It is an arithmetic number, because the mean of its divisors is an integer number (30555555516).

Almost surely, 2^61111111031 is an apocalyptic number.

61111111031 is a deficient number, since it is larger than the sum of its proper divisors (1).

61111111031 is an equidigital number, since it uses as much as digits as its factorization.

61111111031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 17.

Adding to 61111111031 its reverse (13011111116), we get a palindrome (74122222147).

The spelling of 61111111031 in words is "sixty-one billion, one hundred eleven million, one hundred eleven thousand, thirty-one".