61871409 has 12 divisors (see below), whose sum is σ = 89460852. Its totient is φ = 41205600.

The previous prime is 61871399. The next prime is 61871417. The reversal of 61871409 is 90417816.

It can be written as a sum of positive squares in 2 ways, for example, as 55353600 + 6517809 = 7440^2 + 2553^2 .

It is not a de Polignac number, because 61871409 - 2⁴ = 61871393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61871209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7719 + ... + 13539.

It is an arithmetic number, because the mean of its divisors is an integer number (7455071).

Almost surely, 2^61871409 is an apocalyptic number.

It is an amenable number.

61871409 is a deficient number, since it is larger than the sum of its proper divisors (27589443).

61871409 is a wasteful number, since it uses less digits than its factorization.

61871409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7008 (or 7005 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 61871409 is about 7865.8380990203. The cubic root of 61871409 is about 395.5153429531.

It can be divided in two parts, 618 and 71409, that added together give a palindrome (72027).

The spelling of 61871409 in words is "sixty-one million, eight hundred seventy-one thousand, four hundred nine".