81622945 has 12 divisors (see below), whose sum is σ = 98903700. Its totient is φ = 64664160.

The previous prime is 81622921. The next prime is 81622963. The reversal of 81622945 is 54922618.

It can be written as a sum of positive squares in 2 ways, for example, as 18515809 + 63107136 = 4303^2 + 7944^2 .

It is not a de Polignac number, because 81622945 - 2⁹ = 81622433 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 246430 + ... + 246760.

It is an arithmetic number, because the mean of its divisors is an integer number (8241975).

Almost surely, 2^81622945 is an apocalyptic number.

It is an amenable number.

81622945 is a deficient number, since it is larger than the sum of its proper divisors (17280755).

81622945 is an equidigital number, since it uses as much as digits as its factorization.

81622945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816 (or 485 counting only the distinct ones).

The product of its digits is 34560, while the sum is 37.

The square root of 81622945 is about 9034.5417703390. The cubic root of 81622945 is about 433.7812275601.

The spelling of 81622945 in words is "eighty-one million, six hundred twenty-two thousand, nine hundred forty-five".