61971779 has 4 divisors (see below), whose sum is σ = 62006184. Its totient is φ = 61937376.

The previous prime is 61971737. The next prime is 61971797. The reversal of 61971779 is 97717916.

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 61971779 - 2⁸ = 61971523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61971719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14342 + ... + 18155.

It is an arithmetic number, because the mean of its divisors is an integer number (15501546).

Almost surely, 2^61971779 is an apocalyptic number.

61971779 is a deficient number, since it is larger than the sum of its proper divisors (34405).

61971779 is a wasteful number, since it uses less digits than its factorization.

61971779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34404.

The product of its digits is 166698, while the sum is 47.

The square root of 61971779 is about 7872.2156347499. The cubic root of 61971779 is about 395.7291004248.

The spelling of 61971779 in words is "sixty-one million, nine hundred seventy-one thousand, seven hundred seventy-nine".