78215089 has 4 divisors (see below), whose sum is σ = 78275620. Its totient is φ = 78154560.

The previous prime is 78215087. The next prime is 78215101. The reversal of 78215089 is 98051287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60575089 + 17640000 = 7783^2 + 4200^2 .

It is a cyclic number.

It is not a de Polignac number, because 78215089 - 2¹ = 78215087 is a prime.

It is a super-2 number, since 2×78215089² = 12235200294555842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78215083) 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, 28284 + ... + 30925.

It is an arithmetic number, because the mean of its divisors is an integer number (19568905).

Almost surely, 2^78215089 is an apocalyptic number.

It is an amenable number.

78215089 is a deficient number, since it is larger than the sum of its proper divisors (60531).

78215089 is a wasteful number, since it uses less digits than its factorization.

78215089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60530.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 78215089 is about 8843.9294999451. The cubic root of 78215089 is about 427.6582435729.

The spelling of 78215089 in words is "seventy-eight million, two hundred fifteen thousand, eighty-nine".