61947993389 has 2 divisors, whose sum is σ = 61947993390. Its totient is φ = 61947993388.

The previous prime is 61947993337. The next prime is 61947993397. The reversal of 61947993389 is 98339974916.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60954672100 + 993321289 = 246890^2 + 31517^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61947993389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61947993089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30973996694 + 30973996695.

It is an arithmetic number, because the mean of its divisors is an integer number (30973996695).

Almost surely, 2^61947993389 is an apocalyptic number.

It is an amenable number.

61947993389 is a deficient number, since it is larger than the sum of its proper divisors (1).

61947993389 is an equidigital number, since it uses as much as digits as its factorization.

61947993389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 79361856, while the sum is 68.

The spelling of 61947993389 in words is "sixty-one billion, nine hundred forty-seven million, nine hundred ninety-three thousand, three hundred eighty-nine".