78161663 has 4 divisors (see below), whose sum is σ = 78257688. Its totient is φ = 78065640.

The previous prime is 78161647. The next prime is 78161683. The reversal of 78161663 is 36616187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36616187 = 2063 ⋅17749.

It is a cyclic number.

It is not a de Polignac number, because 78161663 - 2⁴ = 78161647 is a prime.

It is a super-2 number, since 2×78161663² = 12218491125851138, which 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 (78161683) 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, 46781 + ... + 48422.

It is an arithmetic number, because the mean of its divisors is an integer number (19564422).

Almost surely, 2^78161663 is an apocalyptic number.

78161663 is a deficient number, since it is larger than the sum of its proper divisors (96025).

78161663 is an equidigital number, since it uses as much as digits as its factorization.

78161663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96024.

The product of its digits is 36288, while the sum is 38.

The square root of 78161663 is about 8840.9084940406. The cubic root of 78161663 is about 427.5608485825.

The spelling of 78161663 in words is "seventy-eight million, one hundred sixty-one thousand, six hundred sixty-three".