81478087 has 2 divisors, whose sum is σ = 81478088. Its totient is φ = 81478086.

The previous prime is 81478079. The next prime is 81478129. The reversal of 81478087 is 78087418.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81478087 - 2³ = 81478079 is a prime.

It is a super-2 number, since 2×81478087² = 13277357322359138, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81478057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40739043 + 40739044.

It is an arithmetic number, because the mean of its divisors is an integer number (40739044).

Almost surely, 2^81478087 is an apocalyptic number.

81478087 is a deficient number, since it is larger than the sum of its proper divisors (1).

81478087 is an equidigital number, since it uses as much as digits as its factorization.

81478087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100352, while the sum is 43.

The square root of 81478087 is about 9026.5213122221. The cubic root of 81478087 is about 433.5244619726.

The spelling of 81478087 in words is "eighty-one million, four hundred seventy-eight thousand, eighty-seven".