81630290 has 16 divisors (see below), whose sum is σ = 167925312. Its totient is φ = 27987504.

The previous prime is 81630287. The next prime is 81630293. The reversal of 81630290 is 9203618.

It is an interprime number because it is at equal distance from previous prime (81630287) and next prime (81630293).

It is not an unprimeable number, because it can be changed into a prime (81630293) 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, 583004 + ... + 583143.

It is an arithmetic number, because the mean of its divisors is an integer number (10495332).

Almost surely, 2^81630290 is an apocalyptic number.

81630290 is an abundant number, since it is smaller than the sum of its proper divisors (86295022).

81630290 is a wasteful number, since it uses less digits than its factorization.

81630290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1166161.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 81630290 is about 9034.9482566310. The cubic root of 81630290 is about 433.7942387200.

The spelling of 81630290 in words is "eighty-one million, six hundred thirty thousand, two hundred ninety".