61397858917 has 2 divisors, whose sum is σ = 61397858918. Its totient is φ = 61397858916.

The previous prime is 61397858891. The next prime is 61397858927. The reversal of 61397858917 is 71985879316.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60280561441 + 1117297476 = 245521^2 + 33426^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61397858917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61397858927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30698929458 + 30698929459.

It is an arithmetic number, because the mean of its divisors is an integer number (30698929459).

Almost surely, 2^61397858917 is an apocalyptic number.

It is an amenable number.

61397858917 is a deficient number, since it is larger than the sum of its proper divisors (1).

61397858917 is an equidigital number, since it uses as much as digits as its factorization.

61397858917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22861440, while the sum is 64.

The spelling of 61397858917 in words is "sixty-one billion, three hundred ninety-seven million, eight hundred fifty-eight thousand, nine hundred seventeen".