81922145 has 4 divisors (see below), whose sum is σ = 98306580. Its totient is φ = 65537712.

The previous prime is 81922123. The next prime is 81922147. The reversal of 81922145 is 54122918.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9314704 + 72607441 = 3052^2 + 8521^2 .

It is a cyclic number.

It is not a de Polignac number, because 81922145 - 2¹⁰ = 81921121 is a prime.

It is a super-2 number, since 2×81922145² = 13422475682802050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81922147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8192210 + ... + 8192219.

It is an arithmetic number, because the mean of its divisors is an integer number (24576645).

Almost surely, 2^81922145 is an apocalyptic number.

It is an amenable number.

81922145 is a deficient number, since it is larger than the sum of its proper divisors (16384435).

81922145 is a wasteful number, since it uses less digits than its factorization.

81922145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16384434.

The product of its digits is 5760, while the sum is 32.

The square root of 81922145 is about 9051.0852940407. The cubic root of 81922145 is about 434.3106092639.

The spelling of 81922145 in words is "eighty-one million, nine hundred twenty-two thousand, one hundred forty-five".