78148761601 has 3 divisors (see below), whose sum is σ = 78149041153. Its totient is φ = 78148482050.

The previous prime is 78148761599. The next prime is 78148761619. The reversal of 78148761601 is 10616784187.

The square root of 78148761601 is 279551.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 78148761601 - 2¹ = 78148761599 is a prime.

It is a super-2 number, since 2×78148761601² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78148761671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 139776 + ... + 419326.

Almost surely, 2^78148761601 is an apocalyptic number.

78148761601 is the 279551-st square number.

78148761601 is the 139776-th centered octagonal number.

It is an amenable number.

78148761601 is a deficient number, since it is larger than the sum of its proper divisors (279552).

78148761601 is an frugal number, since it uses more digits than its factorization.

78148761601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559102 (or 279551 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 49.

Multiplying 78148761601 by its sum of digits (49), we get a square (3829289318449 = 1956857²).

The spelling of 78148761601 in words is "seventy-eight billion, one hundred forty-eight million, seven hundred sixty-one thousand, six hundred one".