78628749109 has 2 divisors, whose sum is σ = 78628749110. Its totient is φ = 78628749108.

The previous prime is 78628749097. The next prime is 78628749113. The reversal of 78628749109 is 90194782687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45001258225 + 33627490884 = 212135^2 + 183378^2 .

It is an emirp because it is prime and its reverse (90194782687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78628749109 - 2¹¹ = 78628747061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78628746109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39314374554 + 39314374555.

It is an arithmetic number, because the mean of its divisors is an integer number (39314374555).

Almost surely, 2^78628749109 is an apocalyptic number.

It is an amenable number.

78628749109 is a deficient number, since it is larger than the sum of its proper divisors (1).

78628749109 is an equidigital number, since it uses as much as digits as its factorization.

78628749109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12192768, while the sum is 61.

It can be divided in two parts, 786287 and 49109, that added together give a square (835396 = 914²).

The spelling of 78628749109 in words is "seventy-eight billion, six hundred twenty-eight million, seven hundred forty-nine thousand, one hundred nine".