81553527 has 16 divisors (see below), whose sum is σ = 131804160. Its totient is φ = 49426200.

The previous prime is 81553489. The next prime is 81553531. The reversal of 81553527 is 72535518.

81553527 is a `hidden beast` number, since 81 + 5 + 53 + 527 = 666.

It is not a de Polignac number, because 81553527 - 2¹⁴ = 81537143 is a prime.

It is a super-2 number, since 2×81553527² = 13301955532279458, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81553491 and 81553500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81553547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136999 + ... + 137592.

It is an arithmetic number, because the mean of its divisors is an integer number (8237760).

Almost surely, 2^81553527 is an apocalyptic number.

81553527 is a deficient number, since it is larger than the sum of its proper divisors (50250633).

81553527 is a wasteful number, since it uses less digits than its factorization.

81553527 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274611 (or 274605 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 81553527 is about 9030.6991423699. The cubic root of 81553527 is about 433.6582198045.

Subtracting from 81553527 its reverse (72535518), we obtain a square (9018009 = 3003²).

The spelling of 81553527 in words is "eighty-one million, five hundred fifty-three thousand, five hundred twenty-seven".