81478475 has 12 divisors (see below), whose sum is σ = 108805536. Its totient is φ = 60168480.

The previous prime is 81478471. The next prime is 81478483. The reversal of 81478475 is 57487418.

It is not a de Polignac number, because 81478475 - 2² = 81478471 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81478471) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 125027 + ... + 125676.

It is an arithmetic number, because the mean of its divisors is an integer number (9067128).

Almost surely, 2^81478475 is an apocalyptic number.

81478475 is a deficient number, since it is larger than the sum of its proper divisors (27327061).

81478475 is a wasteful number, since it uses less digits than its factorization.

81478475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250726 (or 250721 counting only the distinct ones).

The product of its digits is 250880, while the sum is 44.

The square root of 81478475 is about 9026.5428044185. The cubic root of 81478475 is about 433.5251501217.

The spelling of 81478475 in words is "eighty-one million, four hundred seventy-eight thousand, four hundred seventy-five".