78293391 has 16 divisors (see below), whose sum is σ = 114652800. Its totient is φ = 47129120.

The previous prime is 78293353. The next prime is 78293393. The reversal of 78293391 is 19339287.

It is a cyclic number.

It is not a de Polignac number, because 78293391 - 2¹⁹ = 77769103 is a prime.

It is a super-2 number, since 2×78293391² = 12259710148557762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78293393) 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, 3045 + ... + 12878.

It is an arithmetic number, because the mean of its divisors is an integer number (7165800).

Almost surely, 2^78293391 is an apocalyptic number.

78293391 is a deficient number, since it is larger than the sum of its proper divisors (36359409).

78293391 is a wasteful number, since it uses less digits than its factorization.

78293391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16086.

The product of its digits is 81648, while the sum is 42.

The square root of 78293391 is about 8848.3552708964. The cubic root of 78293391 is about 427.8009071257.

The spelling of 78293391 in words is "seventy-eight million, two hundred ninety-three thousand, three hundred ninety-one".