61771499987 has 2 divisors, whose sum is σ = 61771499988. Its totient is φ = 61771499986.

The previous prime is 61771499983. The next prime is 61771500047. The reversal of 61771499987 is 78999417716.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61771499987 - 2² = 61771499983 is a prime.

It is not a weakly prime, because it can be changed into another prime (61771499983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30885749993 + 30885749994.

It is an arithmetic number, because the mean of its divisors is an integer number (30885749994).

Almost surely, 2^61771499987 is an apocalyptic number.

61771499987 is a deficient number, since it is larger than the sum of its proper divisors (1).

61771499987 is an equidigital number, since it uses as much as digits as its factorization.

61771499987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48009024, while the sum is 68.

The spelling of 61771499987 in words is "sixty-one billion, seven hundred seventy-one million, four hundred ninety-nine thousand, nine hundred eighty-seven".