61971887 has 4 divisors (see below), whose sum is σ = 62330280. Its totient is φ = 61613496.

The previous prime is 61971881. The next prime is 61971911. The reversal of 61971887 is 78817916.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61971887 - 2⁶ = 61971823 is a prime.

It is a Duffinian number.

It is a zygodrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61971881) 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 in 3 ways as a sum of consecutive naturals, for example, 178937 + ... + 179282.

It is an arithmetic number, because the mean of its divisors is an integer number (15582570).

Almost surely, 2^61971887 is an apocalyptic number.

61971887 is a deficient number, since it is larger than the sum of its proper divisors (358393).

61971887 is a wasteful number, since it uses less digits than its factorization.

61971887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358392.

The product of its digits is 169344, while the sum is 47.

The square root of 61971887 is about 7872.2224943151. Note that the first 3 decimals coincide. The cubic root of 61971887 is about 395.7293303074.

The spelling of 61971887 in words is "sixty-one million, nine hundred seventy-one thousand, eight hundred eighty-seven".