165978367 has 4 divisors (see below), whose sum is σ = 166353480. Its totient is φ = 165603256.

The previous prime is 165978353. The next prime is 165978383. The reversal of 165978367 is 763879561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 763879561 = 19739 ⋅38699.

It is a cyclic number.

It is not a de Polignac number, because 165978367 - 2¹⁵ = 165945599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165978317) 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, 186892 + ... + 187777.

It is an arithmetic number, because the mean of its divisors is an integer number (41588370).

Almost surely, 2^165978367 is an apocalyptic number.

165978367 is a deficient number, since it is larger than the sum of its proper divisors (375113).

165978367 is an equidigital number, since it uses as much as digits as its factorization.

165978367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375112.

The product of its digits is 1905120, while the sum is 52.

The square root of 165978367 is about 12883.2591761557. The cubic root of 165978367 is about 549.5625910687.

It can be divided in two parts, 16597 and 8367, that added together give a square (24964 = 158²).

The spelling of 165978367 in words is "one hundred sixty-five million, nine hundred seventy-eight thousand, three hundred sixty-seven".