81216457822 has 8 divisors (see below), whose sum is σ = 121942622736. Its totient is φ = 40568916912.

The previous prime is 81216457811. The next prime is 81216457831. The reversal of 81216457822 is 22875461218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81216457822² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19653418 + ... + 19657549.

It is an arithmetic number, because the mean of its divisors is an integer number (15242827842).

Almost surely, 2^81216457822 is an apocalyptic number.

81216457822 is a deficient number, since it is larger than the sum of its proper divisors (40726164914).

81216457822 is a wasteful number, since it uses less digits than its factorization.

81216457822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39312002.

The product of its digits is 430080, while the sum is 46.

The spelling of 81216457822 in words is "eighty-one billion, two hundred sixteen million, four hundred fifty-seven thousand, eight hundred twenty-two".