78105438 has 16 divisors (see below), whose sum is σ = 173567760. Its totient is φ = 26035128.

The previous prime is 78105403. The next prime is 78105491. The reversal of 78105438 is 83450187.

It is a super-2 number, since 2×78105438² = 12200918890343688, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 723145 + ... + 723252.

It is an arithmetic number, because the mean of its divisors is an integer number (10847985).

Almost surely, 2^78105438 is an apocalyptic number.

78105438 is an abundant number, since it is smaller than the sum of its proper divisors (95462322).

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

78105438 is a wasteful number, since it uses less digits than its factorization.

78105438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1446408 (or 1446402 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 78105438 is about 8837.7281017239. The cubic root of 78105438 is about 427.4583031046.

The spelling of 78105438 in words is "seventy-eight million, one hundred five thousand, four hundred thirty-eight".