81255120 has 40 divisors (see below), whose sum is σ = 251891616. Its totient is φ = 21667968.

The previous prime is 81255103. The next prime is 81255127. The reversal of 81255120 is 2155218.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81255127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169042 + ... + 169521.

Almost surely, 2^81255120 is an apocalyptic number.

81255120 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81255120 is an abundant number, since it is smaller than the sum of its proper divisors (170636496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81255120 is a wasteful number, since it uses less digits than its factorization.

81255120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338579 (or 338573 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 81255120 is about 9014.1621906864. The cubic root of 81255120 is about 433.1286502111.

The spelling of 81255120 in words is "eighty-one million, two hundred fifty-five thousand, one hundred twenty".