81420134 has 4 divisors (see below), whose sum is σ = 122130204. Its totient is φ = 40710066.

The previous prime is 81420127. The next prime is 81420179. The reversal of 81420134 is 43102418.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20355032 + ... + 20355035.

It is an arithmetic number, because the mean of its divisors is an integer number (30532551).

Almost surely, 2^81420134 is an apocalyptic number.

81420134 is a deficient number, since it is larger than the sum of its proper divisors (40710070).

81420134 is a wasteful number, since it uses less digits than its factorization.

81420134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40710069.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 81420134 is about 9023.3105898002. The cubic root of 81420134 is about 433.4216531353.

The spelling of 81420134 in words is "eighty-one million, four hundred twenty thousand, one hundred thirty-four".