78774381 has 24 divisors (see below), whose sum is σ = 132250560. Its totient is φ = 44248896.

The previous prime is 78774347. The next prime is 78774383. The reversal of 78774381 is 18347787.

It is a happy number.

It is not a de Polignac number, because 78774381 - 2⁷ = 78774253 is a prime.

It is a super-2 number, since 2×78774381² = 12410806203866322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78774383) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6880 + ... + 14313.

It is an arithmetic number, because the mean of its divisors is an integer number (5510440).

Almost surely, 2^78774381 is an apocalyptic number.

It is an amenable number.

78774381 is a deficient number, since it is larger than the sum of its proper divisors (53476179).

78774381 is a wasteful number, since it uses less digits than its factorization.

78774381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21265 (or 21262 counting only the distinct ones).

The product of its digits is 263424, while the sum is 45.

The square root of 78774381 is about 8875.4932820661. The cubic root of 78774381 is about 428.6751742649.

The spelling of 78774381 in words is "seventy-eight million, seven hundred seventy-four thousand, three hundred eighty-one".