78009281 has 8 divisors (see below), whose sum is σ = 89281920. Its totient is φ = 66768768.

The previous prime is 78009271. The next prime is 78009287. The reversal of 78009281 is 18290087.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 78009281 - 2¹⁴ = 77992897 is a prime.

It is a super-2 number, since 2×78009281² = 12170895844273922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78009287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2576 + ... + 12753.

It is an arithmetic number, because the mean of its divisors is an integer number (11160240).

Almost surely, 2^78009281 is an apocalyptic number.

It is an amenable number.

78009281 is a deficient number, since it is larger than the sum of its proper divisors (11272639).

78009281 is a wasteful number, since it uses less digits than its factorization.

78009281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16063.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 78009281 is about 8832.2862838565. The cubic root of 78009281 is about 427.2828138846.

The spelling of 78009281 in words is "seventy-eight million, nine thousand, two hundred eighty-one".