81378147 has 8 divisors (see below), whose sum is σ = 112245840. Its totient is φ = 52381280.

The previous prime is 81378091. The next prime is 81378151. The reversal of 81378147 is 74187318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81378147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81378047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 467604 + ... + 467777.

It is an arithmetic number, because the mean of its divisors is an integer number (14030730).

Almost surely, 2^81378147 is an apocalyptic number.

81378147 is a gapful number since it is divisible by the number (87) formed by its first and last digit.

81378147 is a deficient number, since it is larger than the sum of its proper divisors (30867693).

81378147 is a wasteful number, since it uses less digits than its factorization.

81378147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935413.

The product of its digits is 37632, while the sum is 39.

The square root of 81378147 is about 9020.9837046743. The cubic root of 81378147 is about 433.3471375616.

The spelling of 81378147 in words is "eighty-one million, three hundred seventy-eight thousand, one hundred forty-seven".