78131287 has 8 divisors (see below), whose sum is σ = 88570160. Its totient is φ = 68325120.

The previous prime is 78131267. The next prime is 78131323. The reversal of 78131287 is 78213187.

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 78131287 - 2¹¹ = 78129239 is a prime.

It is a super-2 number, since 2×78131287² = 12208996016552738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78131257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157914 + ... + 158407.

It is an arithmetic number, because the mean of its divisors is an integer number (11071270).

Almost surely, 2^78131287 is an apocalyptic number.

78131287 is a deficient number, since it is larger than the sum of its proper divisors (10438873).

78131287 is a wasteful number, since it uses less digits than its factorization.

78131287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316353.

The product of its digits is 18816, while the sum is 37.

The square root of 78131287 is about 8839.1904041038. The cubic root of 78131287 is about 427.5054536883.

Subtracting from 78131287 its sum of digits (37), we obtain a triangular number (78131250 = T₁₂₅₀₀).

The spelling of 78131287 in words is "seventy-eight million, one hundred thirty-one thousand, two hundred eighty-seven".