61181431 has 2 divisors, whose sum is σ = 61181432. Its totient is φ = 61181430.

The previous prime is 61181429. The next prime is 61181443. The reversal of 61181431 is 13418116.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61181431 - 2¹ = 61181429 is a prime.

It is a super-2 number, since 2×61181431² = 7486334998415522, which contains 22 as substring.

Together with 61181429, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 61181396 and 61181405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61188431) 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, 30590715 + 30590716.

It is an arithmetic number, because the mean of its divisors is an integer number (30590716).

Almost surely, 2^61181431 is an apocalyptic number.

61181431 is a deficient number, since it is larger than the sum of its proper divisors (1).

61181431 is an equidigital number, since it uses as much as digits as its factorization.

61181431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 25.

The square root of 61181431 is about 7821.8559817987. The cubic root of 61181431 is about 394.0396066757.

Adding to 61181431 its reverse (13418116), we get a palindrome (74599547).

The spelling of 61181431 in words is "sixty-one million, one hundred eighty-one thousand, four hundred thirty-one".