81212769330 has 64 divisors (see below), whose sum is σ = 243005488128. Its totient is φ = 16875380160.

The previous prime is 81212769283. The next prime is 81212769331. The reversal of 81212769330 is 3396721218.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (81212769331) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17576212 + ... + 17580831.

It is an arithmetic number, because the mean of its divisors is an integer number (3796960752).

Almost surely, 2^81212769330 is an apocalyptic number.

81212769330 is an abundant number, since it is smaller than the sum of its proper divisors (161792718798).

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

81212769330 is a wasteful number, since it uses less digits than its factorization.

81212769330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35157071.

The product of its (nonzero) digits is 108864, while the sum is 42.

The spelling of 81212769330 in words is "eighty-one billion, two hundred twelve million, seven hundred sixty-nine thousand, three hundred thirty".