81770755 has 32 divisors (see below), whose sum is σ = 110315520. Its totient is φ = 57684480.

The previous prime is 81770723. The next prime is 81770789. The reversal of 81770755 is 55707718.

It is a happy number.

It is not a de Polignac number, because 81770755 - 2⁵ = 81770723 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 366574 + ... + 366796.

It is an arithmetic number, because the mean of its divisors is an integer number (3447360).

Almost surely, 2^81770755 is an apocalyptic number.

81770755 is a deficient number, since it is larger than the sum of its proper divisors (28544765).

81770755 is a wasteful number, since it uses less digits than its factorization.

81770755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411.

The product of its (nonzero) digits is 68600, while the sum is 40.

The square root of 81770755 is about 9042.7183412954. The cubic root of 81770755 is about 434.0429127154.

The spelling of 81770755 in words is "eighty-one million, seven hundred seventy thousand, seven hundred fifty-five".