61139887 has 2 divisors, whose sum is σ = 61139888. Its totient is φ = 61139886.

The previous prime is 61139879. The next prime is 61139921. The reversal of 61139887 is 78893116.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61139887 - 2³ = 61139879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61139807) 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, 30569943 + 30569944.

It is an arithmetic number, because the mean of its divisors is an integer number (30569944).

Almost surely, 2^61139887 is an apocalyptic number.

61139887 is a deficient number, since it is larger than the sum of its proper divisors (1).

61139887 is an equidigital number, since it uses as much as digits as its factorization.

61139887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 43.

The square root of 61139887 is about 7819.1998951299. The cubic root of 61139887 is about 393.9503983011.

It can be divided in two parts, 61139 and 887, that added together give a palindrome (62026).

The spelling of 61139887 in words is "sixty-one million, one hundred thirty-nine thousand, eight hundred eighty-seven".