78078431 has 2 divisors, whose sum is σ = 78078432. Its totient is φ = 78078430.

The previous prime is 78078409. The next prime is 78078439. The reversal of 78078431 is 13487087.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78078431 - 2¹⁸ = 77816287 is a prime.

It is a super-2 number, since 2×78078431² = 12192482774843522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78078439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39039215 + 39039216.

It is an arithmetic number, because the mean of its divisors is an integer number (39039216).

Almost surely, 2^78078431 is an apocalyptic number.

78078431 is a deficient number, since it is larger than the sum of its proper divisors (1).

78078431 is an equidigital number, since it uses as much as digits as its factorization.

78078431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 78078431 is about 8836.2000316878. The cubic root of 78078431 is about 427.4090291252.

The spelling of 78078431 in words is "seventy-eight million, seventy-eight thousand, four hundred thirty-one".