61081639571 has 2 divisors, whose sum is σ = 61081639572. Its totient is φ = 61081639570.

The previous prime is 61081639561. The next prime is 61081639613. The reversal of 61081639571 is 17593618016.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61081639571 is a prime.

It is not a weakly prime, because it can be changed into another prime (61081639561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30540819785 + 30540819786.

It is an arithmetic number, because the mean of its divisors is an integer number (30540819786).

Almost surely, 2^61081639571 is an apocalyptic number.

61081639571 is a deficient number, since it is larger than the sum of its proper divisors (1).

61081639571 is an equidigital number, since it uses as much as digits as its factorization.

61081639571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 47.

The spelling of 61081639571 in words is "sixty-one billion, eighty-one million, six hundred thirty-nine thousand, five hundred seventy-one".