78105906 has 12 divisors (see below), whose sum is σ = 169229502. Its totient is φ = 26035296.

The previous prime is 78105899. The next prime is 78105913. The reversal of 78105906 is 60950187.

It is an interprime number because it is at equal distance from previous prime (78105899) and next prime (78105913).

It can be written as a sum of positive squares in only one way, i.e., 47403225 + 30702681 = 6885^2 + 5541^2 .

It is a super-2 number, since 2×78105906² = 12201065104161672, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2169591 + ... + 2169626.

Almost surely, 2^78105906 is an apocalyptic number.

78105906 is an abundant number, since it is smaller than the sum of its proper divisors (91123596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78105906 is a wasteful number, since it uses less digits than its factorization.

78105906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4339225 (or 4339222 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 78105906 is about 8837.7545790772. The cubic root of 78105906 is about 427.4591568654.

The spelling of 78105906 in words is "seventy-eight million, one hundred five thousand, nine hundred six".