78148640245666 has 8 divisors (see below), whose sum is σ = 117734851025820. Its totient is φ = 38903689903728.

The previous prime is 78148640245657. The next prime is 78148640245691. The reversal of 78148640245666 is 66654204684187.

It can be written as a sum of positive squares in 2 ways, for example, as 49366713561025 + 28781926684641 = 7026145^2 + 5364879^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×78148640245666² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85315108981 + ... + 85315109896.

Almost surely, 2^{78148640245666} is an apocalyptic number.

78148640245666 is a deficient number, since it is larger than the sum of its proper divisors (39586210780154).

78148640245666 is a wasteful number, since it uses less digits than its factorization.

78148640245666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170630219108.

The product of its (nonzero) digits is 371589120, while the sum is 67.

The spelling of 78148640245666 in words is "seventy-eight trillion, one hundred forty-eight billion, six hundred forty million, two hundred forty-five thousand, six hundred sixty-six".