61971647 has 4 divisors (see below), whose sum is σ = 65617056. Its totient is φ = 58326240.

The previous prime is 61971641. The next prime is 61971677. The reversal of 61971647 is 74617916.

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 61971647 - 2⁸ = 61971391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61971641) 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, 1822679 + ... + 1822712.

It is an arithmetic number, because the mean of its divisors is an integer number (16404264).

Almost surely, 2^61971647 is an apocalyptic number.

61971647 is a deficient number, since it is larger than the sum of its proper divisors (3645409).

61971647 is a wasteful number, since it uses less digits than its factorization.

61971647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3645408.

The product of its digits is 63504, while the sum is 41.

The square root of 61971647 is about 7872.2072508287. The cubic root of 61971647 is about 395.7288194567.

The spelling of 61971647 in words is "sixty-one million, nine hundred seventy-one thousand, six hundred forty-seven".