81551074 has 64 divisors (see below), whose sum is σ = 149610240. Its totient is φ = 32901120.

The previous prime is 81551051. The next prime is 81551087. The reversal of 81551074 is 47015518.

It is a plaindrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 791707 + ... + 791809.

It is an arithmetic number, because the mean of its divisors is an integer number (2337660).

Almost surely, 2^81551074 is an apocalyptic number.

81551074 is a deficient number, since it is larger than the sum of its proper divisors (68059166).

81551074 is a wasteful number, since it uses less digits than its factorization.

81551074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235.

The product of its (nonzero) digits is 5600, while the sum is 31.

The square root of 81551074 is about 9030.5633268363. The cubic root of 81551074 is about 433.6538718451.

It can be divided in two parts, 8155 and 1074, that added together give a palindrome (9229).

The spelling of 81551074 in words is "eighty-one million, five hundred fifty-one thousand, seventy-four".