78641281 has 4 divisors (see below), whose sum is σ = 80470192. Its totient is φ = 76812372.

The previous prime is 78641273. The next prime is 78641287. The reversal of 78641281 is 18214687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18214687 = 67 ⋅271861.

It is a cyclic number.

It is not a de Polignac number, because 78641281 - 2³ = 78641273 is a prime.

It is a super-2 number, since 2×78641281² = 12368902154641922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78641281.

It is not an unprimeable number, because it can be changed into a prime (78641287) 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, 914391 + ... + 914476.

It is an arithmetic number, because the mean of its divisors is an integer number (20117548).

Almost surely, 2^78641281 is an apocalyptic number.

It is an amenable number.

78641281 is a deficient number, since it is larger than the sum of its proper divisors (1828911).

78641281 is a wasteful number, since it uses less digits than its factorization.

78641281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1828910.

The product of its digits is 21504, while the sum is 37.

The square root of 78641281 is about 8867.9919372990. The cubic root of 78641281 is about 428.4336032102.

The spelling of 78641281 in words is "seventy-eight million, six hundred forty-one thousand, two hundred eighty-one".