78205881 has 16 divisors (see below), whose sum is σ = 118207040. Its totient is φ = 45593280.

The previous prime is 78205823. The next prime is 78205889. The reversal of 78205881 is 18850287.

It is not a de Polignac number, because 78205881 - 2¹⁰ = 78204857 is a prime.

It is a super-2 number, since 2×78205881² = 12232319645972322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78205889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52030 + ... + 53511.

It is an arithmetic number, because the mean of its divisors is an integer number (7387940).

Almost surely, 2^78205881 is an apocalyptic number.

It is an amenable number.

78205881 is a deficient number, since it is larger than the sum of its proper divisors (40001159).

78205881 is a wasteful number, since it uses less digits than its factorization.

78205881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105576.

The product of its (nonzero) digits is 35840, while the sum is 39.

The square root of 78205881 is about 8843.4089015492. The cubic root of 78205881 is about 427.6414606576.

The spelling of 78205881 in words is "seventy-eight million, two hundred five thousand, eight hundred eighty-one".