81550626 has 16 divisors (see below), whose sum is σ = 165866400. Its totient is φ = 26722688.

The previous prime is 81550621. The next prime is 81550633. The reversal of 81550626 is 62605518.

It is not an unprimeable number, because it can be changed into a prime (81550621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114831 + ... + 115538.

It is an arithmetic number, because the mean of its divisors is an integer number (10366650).

Almost surely, 2^81550626 is an apocalyptic number.

81550626 is an abundant number, since it is smaller than the sum of its proper divisors (84315774).

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

81550626 is a wasteful number, since it uses less digits than its factorization.

81550626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230433.

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 81550626 is about 9030.5385221481. The cubic root of 81550626 is about 433.6530777526.

The spelling of 81550626 in words is "eighty-one million, five hundred fifty thousand, six hundred twenty-six".