81212896390 has 16 divisors (see below), whose sum is σ = 148185724608. Its totient is φ = 32040156096.

The previous prime is 81212896379. The next prime is 81212896409. The reversal of 81212896390 is 9369821218.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 55624542 + ... + 55626001.

It is an arithmetic number, because the mean of its divisors is an integer number (9261607788).

Almost surely, 2^81212896390 is an apocalyptic number.

81212896390 is a deficient number, since it is larger than the sum of its proper divisors (66972828218).

81212896390 is a wasteful number, since it uses less digits than its factorization.

81212896390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111250623.

The product of its (nonzero) digits is 373248, while the sum is 49.

The spelling of 81212896390 in words is "eighty-one billion, two hundred twelve million, eight hundred ninety-six thousand, three hundred ninety".