81443377 has 4 divisors (see below), whose sum is σ = 81592816. Its totient is φ = 81293940.

The previous prime is 81443363. The next prime is 81443387. The reversal of 81443377 is 77334418.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81443377 - 2⁷ = 81443249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81443347) 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, 73899 + ... + 74992.

It is an arithmetic number, because the mean of its divisors is an integer number (20398204).

Almost surely, 2^81443377 is an apocalyptic number.

It is an amenable number.

81443377 is a deficient number, since it is larger than the sum of its proper divisors (149439).

81443377 is a wasteful number, since it uses less digits than its factorization.

81443377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149438.

The product of its digits is 56448, while the sum is 37.

The square root of 81443377 is about 9024.5984398199. The cubic root of 81443377 is about 433.4628921611.

The spelling of 81443377 in words is "eighty-one million, four hundred forty-three thousand, three hundred seventy-seven".