78353921567 has 4 divisors (see below), whose sum is σ = 80881467456. Its totient is φ = 75826375680.

The previous prime is 78353921563. The next prime is 78353921599. The reversal of 78353921567 is 76512935387.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76512935387 = 7 ⋅10930419341.

It is a cyclic number.

It is not a de Polignac number, because 78353921567 - 2² = 78353921563 is a prime.

It is a super-2 number, since 2×78353921567² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78353921561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1263772898 + ... + 1263772959.

It is an arithmetic number, because the mean of its divisors is an integer number (20220366864).

Almost surely, 2^78353921567 is an apocalyptic number.

78353921567 is a deficient number, since it is larger than the sum of its proper divisors (2527545889).

78353921567 is a wasteful number, since it uses less digits than its factorization.

78353921567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2527545888.

The product of its digits is 9525600, while the sum is 56.

The spelling of 78353921567 in words is "seventy-eight billion, three hundred fifty-three million, nine hundred twenty-one thousand, five hundred sixty-seven".