81377143 has 4 divisors (see below), whose sum is σ = 81523800. Its totient is φ = 81230488.

The previous prime is 81377119. The next prime is 81377167. The reversal of 81377143 is 34177318.

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

It is an interprime number because it is at equal distance from previous prime (81377119) and next prime (81377167).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81377143 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81377099 and 81377108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81377173) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72493 + ... + 73606.

It is an arithmetic number, because the mean of its divisors is an integer number (20380950).

Almost surely, 2^81377143 is an apocalyptic number.

81377143 is a deficient number, since it is larger than the sum of its proper divisors (146657).

81377143 is a wasteful number, since it uses less digits than its factorization.

81377143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146656.

The product of its digits is 14112, while the sum is 34.

The square root of 81377143 is about 9020.9280564696. The cubic root of 81377143 is about 433.3453554193.

The spelling of 81377143 in words is "eighty-one million, three hundred seventy-seven thousand, one hundred forty-three".