81618369830 has 32 divisors (see below), whose sum is σ = 147758298336. Its totient is φ = 32459906304.

The previous prime is 81618369803. The next prime is 81618369839. The reversal of 81618369830 is 3896381618.

It is a happy number.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81618369839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1694642 + ... + 1742138.

It is an arithmetic number, because the mean of its divisors is an integer number (4617446823).

Almost surely, 2^81618369830 is an apocalyptic number.

81618369830 is a deficient number, since it is larger than the sum of its proper divisors (66139928506).

81618369830 is a wasteful number, since it uses less digits than its factorization.

81618369830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48488.

The product of its (nonzero) digits is 1492992, while the sum is 53.

The spelling of 81618369830 in words is "eighty-one billion, six hundred eighteen million, three hundred sixty-nine thousand, eight hundred thirty".