81070155 has 48 divisors (see below), whose sum is σ = 144050400. Its totient is φ = 42169344.

The previous prime is 81070153. The next prime is 81070163. The reversal of 81070155 is 55107018.

It is not a de Polignac number, because 81070155 - 2¹ = 81070153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81070153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 544021 + ... + 544169.

It is an arithmetic number, because the mean of its divisors is an integer number (3001050).

Almost surely, 2^81070155 is an apocalyptic number.

81070155 is a deficient number, since it is larger than the sum of its proper divisors (62980245).

81070155 is a wasteful number, since it uses less digits than its factorization.

81070155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 27.

The square root of 81070155 is about 9003.8966564483. The cubic root of 81070155 is about 432.7997498840.

It can be divided in two parts, 81070 and 155, that added together give a square (81225 = 285²).

The spelling of 81070155 in words is "eighty-one million, seventy thousand, one hundred fifty-five".