61787599949 has 2 divisors, whose sum is σ = 61787599950. Its totient is φ = 61787599948.

The previous prime is 61787599943. The next prime is 61787600009. The reversal of 61787599949 is 94999578716.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57020664100 + 4766935849 = 238790^2 + 69043^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61787599949 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61787599943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30893799974 + 30893799975.

It is an arithmetic number, because the mean of its divisors is an integer number (30893799975).

Almost surely, 2^61787599949 is an apocalyptic number.

It is an amenable number.

61787599949 is a deficient number, since it is larger than the sum of its proper divisors (1).

61787599949 is an equidigital number, since it uses as much as digits as its factorization.

61787599949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 308629440, while the sum is 74.

The spelling of 61787599949 in words is "sixty-one billion, seven hundred eighty-seven million, five hundred ninety-nine thousand, nine hundred forty-nine".