61289887 has 2 divisors, whose sum is σ = 61289888. Its totient is φ = 61289886.

The previous prime is 61289873. The next prime is 61289897. The reversal of 61289887 is 78898216.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61289887 - 2²³ = 52901279 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61289887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61289807) 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, 30644943 + 30644944.

It is an arithmetic number, because the mean of its divisors is an integer number (30644944).

Almost surely, 2^61289887 is an apocalyptic number.

61289887 is a deficient number, since it is larger than the sum of its proper divisors (1).

61289887 is an equidigital number, since it uses as much as digits as its factorization.

61289887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 49.

The square root of 61289887 is about 7828.7857934676. The cubic root of 61289887 is about 394.2723065387.

The spelling of 61289887 in words is "sixty-one million, two hundred eighty-nine thousand, eight hundred eighty-seven".