61811977 has 2 divisors, whose sum is σ = 61811978. Its totient is φ = 61811976.

The previous prime is 61811929. The next prime is 61812007. The reversal of 61811977 is 77911816.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45643536 + 16168441 = 6756^2 + 4021^2 .

It is a cyclic number.

It is not a de Polignac number, because 61811977 - 2¹¹ = 61809929 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61811927) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30905988 + 30905989.

It is an arithmetic number, because the mean of its divisors is an integer number (30905989).

Almost surely, 2^61811977 is an apocalyptic number.

It is an amenable number.

61811977 is a deficient number, since it is larger than the sum of its proper divisors (1).

61811977 is an equidigital number, since it uses as much as digits as its factorization.

61811977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 40.

The square root of 61811977 is about 7862.0593358229. The cubic root of 61811977 is about 395.3886619397.

The spelling of 61811977 in words is "sixty-one million, eight hundred eleven thousand, nine hundred seventy-seven".