81622018 has 8 divisors (see below), whose sum is σ = 122492160. Its totient is φ = 40791300.

The previous prime is 81622001. The next prime is 81622019. The reversal of 81622018 is 81022618.

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

It is not an unprimeable number, because it can be changed into a prime (81622019) 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, 3978 + ... + 13381.

It is an arithmetic number, because the mean of its divisors is an integer number (15311520).

Almost surely, 2^81622018 is an apocalyptic number.

81622018 is a deficient number, since it is larger than the sum of its proper divisors (40870142).

81622018 is a wasteful number, since it uses less digits than its factorization.

81622018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19712.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 81622018 is about 9034.4904670933. The cubic root of 81622018 is about 433.7795853882.

The spelling of 81622018 in words is "eighty-one million, six hundred twenty-two thousand, eighteen".