81377801 has 4 divisors (see below), whose sum is σ = 83270352. Its totient is φ = 79485252.

The previous prime is 81377797. The next prime is 81377819. The reversal of 81377801 is 10877318.

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 81377801 - 2² = 81377797 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81377831) 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, 946211 + ... + 946296.

It is an arithmetic number, because the mean of its divisors is an integer number (20817588).

Almost surely, 2^81377801 is an apocalyptic number.

It is an amenable number.

81377801 is a deficient number, since it is larger than the sum of its proper divisors (1892551).

81377801 is a wasteful number, since it uses less digits than its factorization.

81377801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1892550.

The product of its (nonzero) digits is 9408, while the sum is 35.

The square root of 81377801 is about 9020.9645271445. The cubic root of 81377801 is about 433.3465233986.

The spelling of 81377801 in words is "eighty-one million, three hundred seventy-seven thousand, eight hundred one".