81342775 has 6 divisors (see below), whose sum is σ = 100865072. Its totient is φ = 65074200.

The previous prime is 81342763. The next prime is 81342787. The reversal of 81342775 is 57724318.

It is an interprime number because it is at equal distance from previous prime (81342763) and next prime (81342787).

It is not a de Polignac number, because 81342775 - 2²¹ = 79245623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1626831 + ... + 1626880.

Almost surely, 2^81342775 is an apocalyptic number.

81342775 is a deficient number, since it is larger than the sum of its proper divisors (19522297).

81342775 is a wasteful number, since it uses less digits than its factorization.

81342775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3253721 (or 3253716 counting only the distinct ones).

The product of its digits is 47040, while the sum is 37.

The square root of 81342775 is about 9019.0229515175. The cubic root of 81342775 is about 433.2843419302.

The spelling of 81342775 in words is "eighty-one million, three hundred forty-two thousand, seven hundred seventy-five".