61782289931 has 2 divisors, whose sum is σ = 61782289932. Its totient is φ = 61782289930.

The previous prime is 61782289913. The next prime is 61782289951. The reversal of 61782289931 is 13998228716.

Together with previous prime (61782289913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61782289931 - 2⁶ = 61782289867 is a prime.

It is a super-2 number, since 2×61782289931² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61782289951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30891144965 + 30891144966.

It is an arithmetic number, because the mean of its divisors is an integer number (30891144966).

Almost surely, 2^61782289931 is an apocalyptic number.

61782289931 is a deficient number, since it is larger than the sum of its proper divisors (1).

61782289931 is an equidigital number, since it uses as much as digits as its factorization.

61782289931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2612736, while the sum is 56.

The spelling of 61782289931 in words is "sixty-one billion, seven hundred eighty-two million, two hundred eighty-nine thousand, nine hundred thirty-one".