81655149 has 16 divisors (see below), whose sum is σ = 113367744. Its totient is φ = 52233600.

The previous prime is 81655117. The next prime is 81655153. The reversal of 81655149 is 94155618.

It is not a de Polignac number, because 81655149 - 2⁵ = 81655117 is a prime.

It is a super-3 number, since 3×81655149³ (a number of 25 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81655159) 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, 2062 + ... + 12944.

It is an arithmetic number, because the mean of its divisors is an integer number (7085484).

Almost surely, 2^81655149 is an apocalyptic number.

It is an amenable number.

81655149 is a deficient number, since it is larger than the sum of its proper divisors (31712595).

81655149 is a wasteful number, since it uses less digits than its factorization.

81655149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10988.

The product of its digits is 43200, while the sum is 39.

The square root of 81655149 is about 9036.3238653780. The cubic root of 81655149 is about 433.8382689303.

It can be divided in two parts, 8165514 and 9, that multiplied together give a triangular number (73489626 = T₁₂₁₂₃).

The spelling of 81655149 in words is "eighty-one million, six hundred fifty-five thousand, one hundred forty-nine".