87711949561 has 2 divisors, whose sum is σ = 87711949562. Its totient is φ = 87711949560.

The previous prime is 87711949517. The next prime is 87711949573. The reversal of 87711949561 is 16594911778.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57345401961 + 30366547600 = 239469^2 + 174260^2 .

It is a cyclic number.

It is not a de Polignac number, because 87711949561 - 2⁷ = 87711949433 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 87711949496 and 87711949505.

It is not a weakly prime, because it can be changed into another prime (87711949511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43855974780 + 43855974781.

It is an arithmetic number, because the mean of its divisors is an integer number (43855974781).

Almost surely, 2^87711949561 is an apocalyptic number.

It is an amenable number.

87711949561 is a deficient number, since it is larger than the sum of its proper divisors (1).

87711949561 is an equidigital number, since it uses as much as digits as its factorization.

87711949561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3810240, while the sum is 58.

The spelling of 87711949561 in words is "eighty-seven billion, seven hundred eleven million, nine hundred forty-nine thousand, five hundred sixty-one".