81402059 has 4 divisors (see below), whose sum is σ = 81484704. Its totient is φ = 81319416.

The previous prime is 81402031. The next prime is 81402067. The reversal of 81402059 is 95020418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81402059 - 2¹² = 81397963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81402019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39827 + ... + 41820.

It is an arithmetic number, because the mean of its divisors is an integer number (20371176).

Almost surely, 2^81402059 is an apocalyptic number.

81402059 is a deficient number, since it is larger than the sum of its proper divisors (82645).

81402059 is an equidigital number, since it uses as much as digits as its factorization.

81402059 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82644.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 81402059 is about 9022.3089616794. The cubic root of 81402059 is about 433.3895780380.

The spelling of 81402059 in words is "eighty-one million, four hundred two thousand, fifty-nine".