78338691 has 32 divisors (see below), whose sum is σ = 123776000. Its totient is φ = 48825504.

The previous prime is 78338677. The next prime is 78338693. The reversal of 78338691 is 19683387.

It is a happy number.

It is not a de Polignac number, because 78338691 - 2¹⁰ = 78337667 is a prime.

It is a super-2 number, since 2×78338691² = 12273901015186962, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78338693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39561 + ... + 41493.

It is an arithmetic number, because the mean of its divisors is an integer number (3868000).

Almost surely, 2^78338691 is an apocalyptic number.

78338691 is a deficient number, since it is larger than the sum of its proper divisors (45437309).

78338691 is a wasteful number, since it uses less digits than its factorization.

78338691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2040 (or 2034 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 78338691 is about 8850.9146984930. The cubic root of 78338691 is about 427.8833987403.

The spelling of 78338691 in words is "seventy-eight million, three hundred thirty-eight thousand, six hundred ninety-one".