81761288 has 32 divisors (see below), whose sum is σ = 175497600. Its totient is φ = 34981632.

The previous prime is 81761269. The next prime is 81761369. The reversal of 81761288 is 88216718.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55781 + ... + 57227.

It is an arithmetic number, because the mean of its divisors is an integer number (5484300).

Almost surely, 2^81761288 is an apocalyptic number.

It is an amenable number.

81761288 is an abundant number, since it is smaller than the sum of its proper divisors (93736312).

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

81761288 is a wasteful number, since it uses less digits than its factorization.

81761288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2469 (or 2465 counting only the distinct ones).

The product of its digits is 43008, while the sum is 41.

The square root of 81761288 is about 9042.1948662921. The cubic root of 81761288 is about 434.0261616458.

The spelling of 81761288 in words is "eighty-one million, seven hundred sixty-one thousand, two hundred eighty-eight".