81551160 has 48 divisors (see below), whose sum is σ = 265042440. Its totient is φ = 21746880.

The previous prime is 81551143. The next prime is 81551189. The reversal of 81551160 is 6115518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 112906 + ... + 113625.

Almost surely, 2^81551160 is an apocalyptic number.

It is an amenable number.

81551160 is an abundant number, since it is smaller than the sum of its proper divisors (183491280).

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

81551160 is a wasteful number, since it uses less digits than its factorization.

81551160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226548 (or 226541 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 27.

The square root of 81551160 is about 9030.5680884427. The cubic root of 81551160 is about 433.6540242821.

Adding to 81551160 its reverse (6115518), we get a palindrome (87666678).

The spelling of 81551160 in words is "eighty-one million, five hundred fifty-one thousand, one hundred sixty".